Find the Maximum/Minimum Value f(x)=0.4x^3+1.2x^2-5.2x-6

$f (x) = 0.4 x^{3} + 1.2 x^{2} - 5.2 x - 6$

Step 1

Find the first derivative of the function.

By the Sum Rule, the derivative of $0.4 x^{3} + 1.2 x^{2} - 5.2 x - 6$ with respect to $x$ is $\frac{d}{d x} [0.4 x^{3}] + \frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$ .

$\frac{d}{d x} [0.4 x^{3}] + \frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Evaluate $\frac{d}{d x} [0.4 x^{3}]$ .

Since $0.4$ is constant with respect to $x$ , the derivative of $0.4 x^{3}$ with respect to $x$ is $0.4 \frac{d}{d x} [x^{3}]$ .

$0.4 \frac{d}{d x} [x^{3}] + \frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 3$ .

$0.4 (3 x^{2}) + \frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Multiply $3$ by $0.4$ .

$1.2 x^{2} + \frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Evaluate $\frac{d}{d x} [1.2 x^{2}]$ .

Since $1.2$ is constant with respect to $x$ , the derivative of $1.2 x^{2}$ with respect to $x$ is $1.2 \frac{d}{d x} [x^{2}]$ .

$1.2 x^{2} + 1.2 \frac{d}{d x} [x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$1.2 x^{2} + 1.2 (2 x) + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Multiply $2$ by $1.2$ .

$1.2 x^{2} + 2.4 x + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$

Evaluate $\frac{d}{d x} [- 5.2 x]$ .

Since $- 5.2$ is constant with respect to $x$ , the derivative of $- 5.2 x$ with respect to $x$ is $- 5.2 \frac{d}{d x} [x]$ .

$1.2 x^{2} + 2.4 x - 5.2 \frac{d}{d x} [x] + \frac{d}{d x} [- 6]$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$1.2 x^{2} + 2.4 x - 5.2 \cdot 1 + \frac{d}{d x} [- 6]$

Multiply $- 5.2$ by $1$ .

$1.2 x^{2} + 2.4 x - 5.2 + \frac{d}{d x} [- 6]$

Differentiate using the Constant Rule.

Since $- 6$ is constant with respect to $x$ , the derivative of $- 6$ with respect to $x$ is $0$ .

$1.2 x^{2} + 2.4 x - 5.2 + 0$

Add $1.2 x^{2} + 2.4 x - 5.2$ and $0$ .

$1.2 x^{2} + 2.4 x - 5.2$

Step 2

Find the second derivative of the function.

By the Sum Rule, the derivative of $1.2 x^{2} + 2.4 x - 5.2$ with respect to $x$ is $\frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [2.4 x] + \frac{d}{d x} [- 5.2]$ .

$f'' (x) = \frac{d}{d x} (1.2 x^{2}) + \frac{d}{d x} (2.4 x) + \frac{d}{d x} (- 5.2)$

Evaluate $\frac{d}{d x} [1.2 x^{2}]$ .

Since $1.2$ is constant with respect to $x$ , the derivative of $1.2 x^{2}$ with respect to $x$ is $1.2 \frac{d}{d x} [x^{2}]$ .

$f'' (x) = 1.2 \frac{d}{d x} (x^{2}) + \frac{d}{d x} (2.4 x) + \frac{d}{d x} (- 5.2)$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$f'' (x) = 1.2 (2 x) + \frac{d}{d x} (2.4 x) + \frac{d}{d x} (- 5.2)$

Multiply $2$ by $1.2$ .

$f'' (x) = 2.4 x + \frac{d}{d x} (2.4 x) + \frac{d}{d x} (- 5.2)$

Evaluate $\frac{d}{d x} [2.4 x]$ .

Since $2.4$ is constant with respect to $x$ , the derivative of $2.4 x$ with respect to $x$ is $2.4 \frac{d}{d x} [x]$ .

$f'' (x) = 2.4 x + 2.4 \frac{d}{d x} (x) + \frac{d}{d x} (- 5.2)$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$f'' (x) = 2.4 x + 2.4 \cdot 1 + \frac{d}{d x} (- 5.2)$

Multiply $2.4$ by $1$ .

$f'' (x) = 2.4 x + 2.4 + \frac{d}{d x} (- 5.2)$

Differentiate using the Constant Rule.

Since $- 5.2$ is constant with respect to $x$ , the derivative of $- 5.2$ with respect to $x$ is $0$ .

$f'' (x) = 2.4 x + 2.4 + 0$

Add $2.4 x + 2.4$ and $0$ .

$f'' (x) = 2.4 x + 2.4$

Step 3

To find the local maximum and minimum values of the function, set the derivative equal to $0$ and solve.

$1.2 x^{2} + 2.4 x - 5.2 = 0$

Step 4

Find the first derivative.

By the Sum Rule, the derivative of $0.4 x^{3} + 1.2 x^{2} - 5.2 x - 6$ with respect to $x$ is $\frac{d}{d x} [0.4 x^{3}] + \frac{d}{d x} [1.2 x^{2}] + \frac{d}{d x} [- 5.2 x] + \frac{d}{d x} [- 6]$ .

$f' (x) = \frac{d}{d x} (0.4 x^{3}) + \frac{d}{d x} (1.2 x^{2}) + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Evaluate $\frac{d}{d x} [0.4 x^{3}]$ .

Since $0.4$ is constant with respect to $x$ , the derivative of $0.4 x^{3}$ with respect to $x$ is $0.4 \frac{d}{d x} [x^{3}]$ .

$f' (x) = 0.4 \frac{d}{d x} (x^{3}) + \frac{d}{d x} (1.2 x^{2}) + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 3$ .

$f' (x) = 0.4 (3 x^{2}) + \frac{d}{d x} (1.2 x^{2}) + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Multiply $3$ by $0.4$ .

$f' (x) = 1.2 x^{2} + \frac{d}{d x} (1.2 x^{2}) + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Evaluate $\frac{d}{d x} [1.2 x^{2}]$ .

Since $1.2$ is constant with respect to $x$ , the derivative of $1.2 x^{2}$ with respect to $x$ is $1.2 \frac{d}{d x} [x^{2}]$ .

$f' (x) = 1.2 x^{2} + 1.2 \frac{d}{d x} (x^{2}) + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$f' (x) = 1.2 x^{2} + 1.2 (2 x) + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Multiply $2$ by $1.2$ .

$f' (x) = 1.2 x^{2} + 2.4 x + \frac{d}{d x} (- 5.2 x) + \frac{d}{d x} (- 6)$

Evaluate $\frac{d}{d x} [- 5.2 x]$ .

Since $- 5.2$ is constant with respect to $x$ , the derivative of $- 5.2 x$ with respect to $x$ is $- 5.2 \frac{d}{d x} [x]$ .

$f' (x) = 1.2 x^{2} + 2.4 x - 5.2 \frac{d}{d x} x + \frac{d}{d x} (- 6)$

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$f' (x) = 1.2 x^{2} + 2.4 x - 5.2 \cdot 1 + \frac{d}{d x} (- 6)$

Multiply $- 5.2$ by $1$ .

$f' (x) = 1.2 x^{2} + 2.4 x - 5.2 + \frac{d}{d x} (- 6)$

Differentiate using the Constant Rule.

Since $- 6$ is constant with respect to $x$ , the derivative of $- 6$ with respect to $x$ is $0$ .

$f' (x) = 1.2 x^{2} + 2.4 x - 5.2 + 0$

Add $1.2 x^{2} + 2.4 x - 5.2$ and $0$ .

$f' (x) = 1.2 x^{2} + 2.4 x - 5.2$

The first derivative of $f (x)$ with respect to $x$ is $1.2 x^{2} + 2.4 x - 5.2$ .

$1.2 x^{2} + 2.4 x - 5.2$

Step 5

Set the first derivative equal to $0$ then solve the equation $1.2 x^{2} + 2.4 x - 5.2 = 0$ .

Set the first derivative equal to $0$ .

$1.2 x^{2} + 2.4 x - 5.2 = 0$

Factor $0.4$ out of $1.2 x^{2} + 2.4 x - 5.2$ .

Factor $0.4$ out of $1.2 x^{2}$ .

$0.4 (3 x^{2}) + 2.4 x - 5.2 = 0$

Factor $0.4$ out of $2.4 x$ .

$0.4 (3 x^{2}) + 0.4 (6 x) - 5.2 = 0$

Factor $0.4$ out of $- 5.2$ .

$0.4 (3 x^{2}) + 0.4 (6 x) + 0.4 (- 13) = 0$

Factor $0.4$ out of $0.4 (3 x^{2}) + 0.4 (6 x)$ .

$0.4 (3 x^{2} + 6 x) + 0.4 (- 13) = 0$

Factor $0.4$ out of $0.4 (3 x^{2} + 6 x) + 0.4 (- 13)$ .

$0.4 (3 x^{2} + 6 x - 13) = 0$

Divide each term in $0.4 (3 x^{2} + 6 x - 13) = 0$ by $0.4$ and simplify.

Divide each term in $0.4 (3 x^{2} + 6 x - 13) = 0$ by $0.4$ .

$\frac{0.4 (3 x^{2} + 6 x - 13)}{0.4} = \frac{0}{0.4}$

Simplify the left side.

Cancel the common factor of $0.4$ .

Cancel the common factor.

$\frac{0.4 (3 x^{2} + 6 x - 13)}{0.4} = \frac{0}{0.4}$

Divide $3 x^{2} + 6 x - 13$ by $1$ .

$3 x^{2} + 6 x - 13 = \frac{0}{0.4}$

Simplify the right side.

Divide $0$ by $0.4$ .

$3 x^{2} + 6 x - 13 = 0$

Use the quadratic formula to find the solutions.

$\frac{- b \pm \sqrt{b^{2} - 4 (a c)}}{2 a}$

Substitute the values $a = 3$ , $b = 6$ , and $c = - 13$ into the quadratic formula and solve for $x$ .

$\frac{- 6 \pm \sqrt{6^{2} - 4 \cdot (3 \cdot - 13)}}{2 \cdot 3}$

Simplify.

Simplify the numerator.

Raise $6$ to the power of $2$ .

$x = \frac{- 6 \pm \sqrt{36 - 4 \cdot 3 \cdot - 13}}{2 \cdot 3}$

Multiply $- 4 \cdot 3 \cdot - 13$ .

Multiply $- 4$ by $3$ .

$x = \frac{- 6 \pm \sqrt{36 - 12 \cdot - 13}}{2 \cdot 3}$

Multiply $- 12$ by $- 13$ .

$x = \frac{- 6 \pm \sqrt{36 + 156}}{2 \cdot 3}$

Add $36$ and $156$ .

$x = \frac{- 6 \pm \sqrt{192}}{2 \cdot 3}$

Rewrite $192$ as $8^{2} \cdot 3$ .

Factor $64$ out of $192$ .

$x = \frac{- 6 \pm \sqrt{64 (3)}}{2 \cdot 3}$

Rewrite $64$ as $8^{2}$ .

$x = \frac{- 6 \pm \sqrt{8^{2} \cdot 3}}{2 \cdot 3}$

Pull terms out from under the radical.

$x = \frac{- 6 \pm 8 \sqrt{3}}{2 \cdot 3}$

Multiply $2$ by $3$ .

$x = \frac{- 6 \pm 8 \sqrt{3}}{6}$

Simplify $\frac{- 6 \pm 8 \sqrt{3}}{6}$ .

$x = \frac{- 3 \pm 4 \sqrt{3}}{3}$

Simplify the expression to solve for the $+$ portion of the $\pm$ .

Simplify the numerator.

Raise $6$ to the power of $2$ .

$x = \frac{- 6 \pm \sqrt{36 - 4 \cdot 3 \cdot - 13}}{2 \cdot 3}$

Multiply $- 4 \cdot 3 \cdot - 13$ .

Multiply $- 4$ by $3$ .

$x = \frac{- 6 \pm \sqrt{36 - 12 \cdot - 13}}{2 \cdot 3}$

Multiply $- 12$ by $- 13$ .

$x = \frac{- 6 \pm \sqrt{36 + 156}}{2 \cdot 3}$

Add $36$ and $156$ .

$x = \frac{- 6 \pm \sqrt{192}}{2 \cdot 3}$

Rewrite $192$ as $8^{2} \cdot 3$ .

Factor $64$ out of $192$ .

$x = \frac{- 6 \pm \sqrt{64 (3)}}{2 \cdot 3}$

Rewrite $64$ as $8^{2}$ .

$x = \frac{- 6 \pm \sqrt{8^{2} \cdot 3}}{2 \cdot 3}$

Pull terms out from under the radical.

$x = \frac{- 6 \pm 8 \sqrt{3}}{2 \cdot 3}$

Multiply $2$ by $3$ .

$x = \frac{- 6 \pm 8 \sqrt{3}}{6}$

Simplify $\frac{- 6 \pm 8 \sqrt{3}}{6}$ .

$x = \frac{- 3 \pm 4 \sqrt{3}}{3}$

Change the $\pm$ to $+$ .

$x = \frac{- 3 + 4 \sqrt{3}}{3}$

Rewrite $- 3$ as $- 1 (3)$ .

$x = \frac{- 1 \cdot 3 + 4 \sqrt{3}}{3}$

Factor $- 1$ out of $4 \sqrt{3}$ .

$x = \frac{- 1 \cdot 3 - (- 4 \sqrt{3})}{3}$

Factor $- 1$ out of $- 1 (3) - (- 4 \sqrt{3})$ .

$x = \frac{- 1 (3 - 4 \sqrt{3})}{3}$

Move the negative in front of the fraction.

$x = - \frac{3 - 4 \sqrt{3}}{3}$

Simplify the expression to solve for the $-$ portion of the $\pm$ .

Simplify the numerator.

Raise $6$ to the power of $2$ .

$x = \frac{- 6 \pm \sqrt{36 - 4 \cdot 3 \cdot - 13}}{2 \cdot 3}$

Multiply $- 4 \cdot 3 \cdot - 13$ .

Multiply $- 4$ by $3$ .

$x = \frac{- 6 \pm \sqrt{36 - 12 \cdot - 13}}{2 \cdot 3}$

Multiply $- 12$ by $- 13$ .

$x = \frac{- 6 \pm \sqrt{36 + 156}}{2 \cdot 3}$

Add $36$ and $156$ .

$x = \frac{- 6 \pm \sqrt{192}}{2 \cdot 3}$

Rewrite $192$ as $8^{2} \cdot 3$ .

Factor $64$ out of $192$ .

$x = \frac{- 6 \pm \sqrt{64 (3)}}{2 \cdot 3}$

Rewrite $64$ as $8^{2}$ .

$x = \frac{- 6 \pm \sqrt{8^{2} \cdot 3}}{2 \cdot 3}$

Pull terms out from under the radical.

$x = \frac{- 6 \pm 8 \sqrt{3}}{2 \cdot 3}$

Multiply $2$ by $3$ .

$x = \frac{- 6 \pm 8 \sqrt{3}}{6}$

Simplify $\frac{- 6 \pm 8 \sqrt{3}}{6}$ .

$x = \frac{- 3 \pm 4 \sqrt{3}}{3}$

Change the $\pm$ to $-$ .

$x = \frac{- 3 - 4 \sqrt{3}}{3}$

Rewrite $- 3$ as $- 1 (3)$ .

$x = \frac{- 1 \cdot 3 - 4 \sqrt{3}}{3}$

Factor $- 1$ out of $- 4 \sqrt{3}$ .

$x = \frac{- 1 \cdot 3 - (4 \sqrt{3})}{3}$

Factor $- 1$ out of $- 1 (3) - (4 \sqrt{3})$ .

$x = \frac{- 1 (3 + 4 \sqrt{3})}{3}$

Move the negative in front of the fraction.

$x = - \frac{3 + 4 \sqrt{3}}{3}$

The final answer is the combination of both solutions.

$x = - \frac{3 - 4 \sqrt{3}}{3}, - \frac{3 + 4 \sqrt{3}}{3}$

Step 6

Find the values where the derivative is undefined.

The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.

Step 7

Critical points to evaluate.

$x = - \frac{3 - 4 \sqrt{3}}{3}, - \frac{3 + 4 \sqrt{3}}{3}$

Step 8

Evaluate the second derivative at $x = - \frac{3 - 4 \sqrt{3}}{3}$ . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.

$2.4 (- \frac{3 - 4 \sqrt{3}}{3}) + 2.4$

Step 9

Evaluate the second derivative.

Simplify each term.

Multiply $2.4 (- \frac{3 - 4 \sqrt{3}}{3})$ .

Multiply $- 1$ by $2.4$ .

$- 2.4 \frac{3 - 4 \sqrt{3}}{3} + 2.4$

Combine $- 2.4$ and $\frac{3 - 4 \sqrt{3}}{3}$ .

$\frac{- 2.4 (3 - 4 \sqrt{3})}{3} + 2.4$

Multiply $- 2.4$ by $3 - 4 \sqrt{3}$ .

$\frac{9.42768775}{3} + 2.4$

Divide $9.42768775$ by $3$ .

$3.14256258 + 2.4$

Add $3.14256258$ and $2.4$ .

$5.54256258$

Step 10

$x = - \frac{3 - 4 \sqrt{3}}{3}$ is a local minimum because the value of the second derivative is positive. This is referred to as the second derivative test.

$x = - \frac{3 - 4 \sqrt{3}}{3}$ is a local minimum

Step 11

Find the y-value when $x = - \frac{3 - 4 \sqrt{3}}{3}$ .

Replace the variable $x$ with $- \frac{3 - 4 \sqrt{3}}{3}$ in the expression.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 {(- \frac{3 - 4 \sqrt{3}}{3})}^{3} + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Simplify the result.

Simplify each term.

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

Apply the product rule to $- \frac{3 - 4 \sqrt{3}}{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 ({(- 1)}^{3} {(\frac{3 - 4 \sqrt{3}}{3})}^{3}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $\frac{3 - 4 \sqrt{3}}{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 ({(- 1)}^{3} (\frac{{(3 - 4 \sqrt{3})}^{3}}{3^{3}})) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $- 1$ to the power of $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{{(3 - 4 \sqrt{3})}^{3}}{3^{3}}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{{(3 - 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Use the Binomial Theorem.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{3^{3} + 3 \cdot (3^{2} (- 4 \sqrt{3})) + 3 \cdot (3 {(- 4 \sqrt{3})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Simplify each term.

Raise $3$ to the power of $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 3 \cdot (3^{2} (- 4 \sqrt{3})) + 3 \cdot (3 {(- 4 \sqrt{3})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $3^{2}$ by adding the exponents.

Multiply $3$ by $3^{2}$ .

Raise $3$ to the power of $1$ .

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 3^{1 + 2} (- 4 \sqrt{3}) + 3 \cdot (3 {(- 4 \sqrt{3})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Add $1$ and $2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 3^{3} (- 4 \sqrt{3}) + 3 \cdot (3 {(- 4 \sqrt{3})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 27 (- 4 \sqrt{3}) + 3 \cdot (3 {(- 4 \sqrt{3})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $- 4$ by $27$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 3 \cdot (3 {(- 4 \sqrt{3})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 {(- 4 \sqrt{3})}^{2} + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $- 4 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 ({(- 4)}^{2} {\sqrt{3}}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $- 4$ to the power of $2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 (16 {\sqrt{3}}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite ${\sqrt{3}}^{2}$ as $3$ .

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{3}$ as $3^{\frac{1}{2}}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 (16 {(3^{\frac{1}{2}})}^{2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 (16 \cdot 3^{\frac{1}{2} \cdot 2}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Combine $\frac{1}{2}$ and $2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 (16 \cdot 3^{\frac{2}{2}}) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $2$ .

Cancel the common factor.

Rewrite the expression.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 (16 \cdot 3) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Evaluate the exponent.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 (16 \cdot 3) + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $9 (16 \cdot 3)$ .

Multiply $16$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 9 \cdot 48 + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $9$ by $48$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 + {(- 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $- 4 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 + {(- 4)}^{3} {\sqrt{3}}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $- 4$ to the power of $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 64 {\sqrt{3}}^{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite ${\sqrt{3}}^{3}$ as $\sqrt{3^{3}}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 64 \sqrt{3^{3}}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 64 \sqrt{27}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite $27$ as $3^{2} \cdot 3$ .

Factor $9$ out of $27$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 64 \sqrt{9 (3)}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite $9$ as $3^{2}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 64 \sqrt{3^{2} \cdot 3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Pull terms out from under the radical.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 64 (3 \sqrt{3})}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $- 64$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 - 108 \sqrt{3} + 432 - 192 \sqrt{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Add $27$ and $432$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{459 - 108 \sqrt{3} - 192 \sqrt{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Subtract $192 \sqrt{3}$ from $- 108 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{459 - 300 \sqrt{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $459 - 300 \sqrt{3}$ and $27$ .

Factor $3$ out of $459$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153) - 300 \sqrt{3}}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $- 300 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153) + 3 (- 100 \sqrt{3})}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $3 (153) + 3 (- 100 \sqrt{3})$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153 - 100 \sqrt{3})}{27}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factors.

Factor $3$ out of $27$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153 - 100 \sqrt{3})}{3 \cdot 9}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factor.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153 - 100 \sqrt{3})}{3 \cdot 9}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite the expression.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.4 (- \frac{153 - 100 \sqrt{3}}{9}) + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $0.4 (- \frac{153 - 100 \sqrt{3}}{9})$ .

Multiply $- 1$ by $0.4$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = - 0.4 \frac{153 - 100 \sqrt{3}}{9} + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Combine $- 0.4$ and $\frac{153 - 100 \sqrt{3}}{9}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = \frac{- 0.4 (153 - 100 \sqrt{3})}{9} + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $- 0.4$ by $153 - 100 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = \frac{8.0820323}{9} + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Divide $8.0820323$ by $9$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 {(- \frac{3 - 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

Apply the product rule to $- \frac{3 - 4 \sqrt{3}}{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 ({(- 1)}^{2} {(\frac{3 - 4 \sqrt{3}}{3})}^{2}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $\frac{3 - 4 \sqrt{3}}{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 ({(- 1)}^{2} (\frac{{(3 - 4 \sqrt{3})}^{2}}{3^{2}})) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $- 1$ to the power of $2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (1 (\frac{{(3 - 4 \sqrt{3})}^{2}}{3^{2}})) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $\frac{{(3 - 4 \sqrt{3})}^{2}}{3^{2}}$ by $1$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{{(3 - 4 \sqrt{3})}^{2}}{3^{2}}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{{(3 - 4 \sqrt{3})}^{2}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite ${(3 - 4 \sqrt{3})}^{2}$ as $(3 - 4 \sqrt{3}) (3 - 4 \sqrt{3})$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{(3 - 4 \sqrt{3}) (3 - 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Expand $(3 - 4 \sqrt{3}) (3 - 4 \sqrt{3})$ using the FOIL Method.

Apply the distributive property.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 (3 - 4 \sqrt{3}) - 4 \sqrt{3} (3 - 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the distributive property.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 \cdot 3 + 3 (- 4 \sqrt{3}) - 4 \sqrt{3} (3 - 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the distributive property.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 \cdot 3 + 3 (- 4 \sqrt{3}) - 4 \sqrt{3} \cdot 3 - 4 \sqrt{3} (- 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Simplify and combine like terms.

Simplify each term.

Multiply $3$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 + 3 (- 4 \sqrt{3}) - 4 \sqrt{3} \cdot 3 - 4 \sqrt{3} (- 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $- 4$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 4 \sqrt{3} \cdot 3 - 4 \sqrt{3} (- 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $- 4$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} - 4 \sqrt{3} (- 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $- 4 \sqrt{3} (- 4 \sqrt{3})$ .

Multiply $- 4$ by $- 4$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 \sqrt{3} \sqrt{3}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $\sqrt{3}$ to the power of $1$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 (\sqrt{3} \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Raise $\sqrt{3}$ to the power of $1$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 (\sqrt{3} \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 {\sqrt{3}}^{1 + 1}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Add $1$ and $1$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 {\sqrt{3}}^{2}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite ${\sqrt{3}}^{2}$ as $3$ .

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{3}$ as $3^{\frac{1}{2}}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 {(3^{\frac{1}{2}})}^{2}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 \cdot 3^{\frac{1}{2} \cdot 2}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Combine $\frac{1}{2}$ and $2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 \cdot 3^{\frac{2}{2}}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $2$ .

Cancel the common factor.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 \cdot 3^{\frac{2}{2}}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite the expression.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 \cdot 3}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Evaluate the exponent.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 16 \cdot 3}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $16$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{9 - 12 \sqrt{3} - 12 \sqrt{3} + 48}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Add $9$ and $48$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{57 - 12 \sqrt{3} - 12 \sqrt{3}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Subtract $12 \sqrt{3}$ from $- 12 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{57 - 24 \sqrt{3}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $57 - 24 \sqrt{3}$ and $9$ .

Factor $3$ out of $57$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 (19) - 24 \sqrt{3}}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $- 24 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 (19) + 3 (- 8 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $3 (19) + 3 (- 8 \sqrt{3})$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 (19 - 8 \sqrt{3})}{9}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factors.

Factor $3$ out of $9$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 (19 - 8 \sqrt{3})}{3 \cdot 3}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Cancel the common factor.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{3 (19 - 8 \sqrt{3})}{3 \cdot 3}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Rewrite the expression.

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 1.2 (\frac{19 - 8 \sqrt{3}}{3}) - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $1.2 \frac{19 - 8 \sqrt{3}}{3}$ .

Combine $1.2$ and $\frac{19 - 8 \sqrt{3}}{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + \frac{1.2 (19 - 8 \sqrt{3})}{3} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $1.2$ by $19 - 8 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + \frac{6.17231224}{3} - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Divide $6.17231224$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 2.05743741 - 5.2 (- \frac{3 - 4 \sqrt{3}}{3}) - 6$

Multiply $- 5.2 (- \frac{3 - 4 \sqrt{3}}{3})$ .

Multiply $- 1$ by $- 5.2$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 2.05743741 + 5.2 (\frac{3 - 4 \sqrt{3}}{3}) - 6$

Combine $5.2$ and $\frac{3 - 4 \sqrt{3}}{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 2.05743741 + \frac{5.2 (3 - 4 \sqrt{3})}{3} - 6$

Multiply $5.2$ by $3 - 4 \sqrt{3}$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 2.05743741 + \frac{- 20.42665679}{3} - 6$

Divide $- 20.42665679$ by $3$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 0.89800358 + 2.05743741 - 6.80888559 - 6$

Simplify by adding and subtracting.

Add $0.89800358$ and $2.05743741$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = 2.955441 - 6.80888559 - 6$

Subtract $6.80888559$ from $2.955441$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = - 3.85344459 - 6$

Subtract $6$ from $- 3.85344459$ .

$f (- \frac{3 - 4 \sqrt{3}}{3}) = - 9.85344459$

The final answer is $- 9.85344459$ .

$y = - 9.85344459$

Step 12

Evaluate the second derivative at $x = - \frac{3 + 4 \sqrt{3}}{3}$ . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.

$2.4 (- \frac{3 + 4 \sqrt{3}}{3}) + 2.4$

Step 13

Evaluate the second derivative.

Simplify each term.

Multiply $2.4 (- \frac{3 + 4 \sqrt{3}}{3})$ .

Multiply $- 1$ by $2.4$ .

$- 2.4 \frac{3 + 4 \sqrt{3}}{3} + 2.4$

Combine $- 2.4$ and $\frac{3 + 4 \sqrt{3}}{3}$ .

$\frac{- 2.4 (3 + 4 \sqrt{3})}{3} + 2.4$

Multiply $- 2.4$ by $3 + 4 \sqrt{3}$ .

$\frac{- 23.82768775}{3} + 2.4$

Divide $- 23.82768775$ by $3$ .

$- 7.94256258 + 2.4$

Add $- 7.94256258$ and $2.4$ .

$- 5.54256258$

Step 14

$x = - \frac{3 + 4 \sqrt{3}}{3}$ is a local maximum because the value of the second derivative is negative. This is referred to as the second derivative test.

$x = - \frac{3 + 4 \sqrt{3}}{3}$ is a local maximum

Step 15

Find the y-value when $x = - \frac{3 + 4 \sqrt{3}}{3}$ .

Replace the variable $x$ with $- \frac{3 + 4 \sqrt{3}}{3}$ in the expression.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 {(- \frac{3 + 4 \sqrt{3}}{3})}^{3} + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Simplify the result.

Simplify each term.

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

Apply the product rule to $- \frac{3 + 4 \sqrt{3}}{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 ({(- 1)}^{3} {(\frac{3 + 4 \sqrt{3}}{3})}^{3}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $\frac{3 + 4 \sqrt{3}}{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 ({(- 1)}^{3} (\frac{{(3 + 4 \sqrt{3})}^{3}}{3^{3}})) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $- 1$ to the power of $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{{(3 + 4 \sqrt{3})}^{3}}{3^{3}}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{{(3 + 4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Use the Binomial Theorem.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{3^{3} + 3 \cdot (3^{2} (4 \sqrt{3})) + 3 \cdot (3 {(4 \sqrt{3})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Simplify each term.

Raise $3$ to the power of $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 3 \cdot (3^{2} (4 \sqrt{3})) + 3 \cdot (3 {(4 \sqrt{3})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $3^{2}$ by adding the exponents.

Multiply $3$ by $3^{2}$ .

Raise $3$ to the power of $1$ .

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 3^{1 + 2} (4 \sqrt{3}) + 3 \cdot (3 {(4 \sqrt{3})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Add $1$ and $2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 3^{3} (4 \sqrt{3}) + 3 \cdot (3 {(4 \sqrt{3})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 27 (4 \sqrt{3}) + 3 \cdot (3 {(4 \sqrt{3})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $4$ by $27$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 3 \cdot (3 {(4 \sqrt{3})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 {(4 \sqrt{3})}^{2} + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $4 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (4^{2} {\sqrt{3}}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $4$ to the power of $2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (16 {\sqrt{3}}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite ${\sqrt{3}}^{2}$ as $3$ .

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{3}$ as $3^{\frac{1}{2}}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (16 {(3^{\frac{1}{2}})}^{2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (16 \cdot 3^{\frac{1}{2} \cdot 2}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Combine $\frac{1}{2}$ and $2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (16 \cdot 3^{\frac{2}{2}}) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $2$ .

Cancel the common factor.

Rewrite the expression.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (16 \cdot 3) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Evaluate the exponent.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 (16 \cdot 3) + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $9 (16 \cdot 3)$ .

Multiply $16$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 9 \cdot 48 + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $9$ by $48$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + {(4 \sqrt{3})}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $4 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 4^{3} {\sqrt{3}}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $4$ to the power of $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 64 {\sqrt{3}}^{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite ${\sqrt{3}}^{3}$ as $\sqrt{3^{3}}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 64 \sqrt{3^{3}}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 64 \sqrt{27}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite $27$ as $3^{2} \cdot 3$ .

Factor $9$ out of $27$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 64 \sqrt{9 (3)}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite $9$ as $3^{2}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 64 \sqrt{3^{2} \cdot 3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Pull terms out from under the radical.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 64 (3 \sqrt{3})}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $64$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{27 + 108 \sqrt{3} + 432 + 192 \sqrt{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Add $27$ and $432$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{459 + 108 \sqrt{3} + 192 \sqrt{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Add $108 \sqrt{3}$ and $192 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{459 + 300 \sqrt{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $459 + 300 \sqrt{3}$ and $27$ .

Factor $3$ out of $459$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153) + 300 \sqrt{3}}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $300 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153) + 3 (100 \sqrt{3})}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $3 (153) + 3 (100 \sqrt{3})$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153 + 100 \sqrt{3})}{27}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factors.

Factor $3$ out of $27$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153 + 100 \sqrt{3})}{3 \cdot 9}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factor.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{3 (153 + 100 \sqrt{3})}{3 \cdot 9}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite the expression.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 0.4 (- \frac{153 + 100 \sqrt{3}}{9}) + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $0.4 (- \frac{153 + 100 \sqrt{3}}{9})$ .

Multiply $- 1$ by $0.4$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 0.4 \frac{153 + 100 \sqrt{3}}{9} + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Combine $- 0.4$ and $\frac{153 + 100 \sqrt{3}}{9}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = \frac{- 0.4 (153 + 100 \sqrt{3})}{9} + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $- 0.4$ by $153 + 100 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = \frac{- 130.4820323}{9} + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Divide $- 130.4820323$ by $9$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 {(- \frac{3 + 4 \sqrt{3}}{3})}^{2} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

Apply the product rule to $- \frac{3 + 4 \sqrt{3}}{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 ({(- 1)}^{2} {(\frac{3 + 4 \sqrt{3}}{3})}^{2}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the product rule to $\frac{3 + 4 \sqrt{3}}{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 ({(- 1)}^{2} (\frac{{(3 + 4 \sqrt{3})}^{2}}{3^{2}})) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $- 1$ to the power of $2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (1 (\frac{{(3 + 4 \sqrt{3})}^{2}}{3^{2}})) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $\frac{{(3 + 4 \sqrt{3})}^{2}}{3^{2}}$ by $1$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{{(3 + 4 \sqrt{3})}^{2}}{3^{2}}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $3$ to the power of $2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{{(3 + 4 \sqrt{3})}^{2}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite ${(3 + 4 \sqrt{3})}^{2}$ as $(3 + 4 \sqrt{3}) (3 + 4 \sqrt{3})$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{(3 + 4 \sqrt{3}) (3 + 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Expand $(3 + 4 \sqrt{3}) (3 + 4 \sqrt{3})$ using the FOIL Method.

Apply the distributive property.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 (3 + 4 \sqrt{3}) + 4 \sqrt{3} (3 + 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the distributive property.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 \cdot 3 + 3 (4 \sqrt{3}) + 4 \sqrt{3} (3 + 4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the distributive property.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 \cdot 3 + 3 (4 \sqrt{3}) + 4 \sqrt{3} \cdot 3 + 4 \sqrt{3} (4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Simplify and combine like terms.

Simplify each term.

Multiply $3$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 3 (4 \sqrt{3}) + 4 \sqrt{3} \cdot 3 + 4 \sqrt{3} (4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $4$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 4 \sqrt{3} \cdot 3 + 4 \sqrt{3} (4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $3$ by $4$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 4 \sqrt{3} (4 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $4 \sqrt{3} (4 \sqrt{3})$ .

Multiply $4$ by $4$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 \sqrt{3} \sqrt{3}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $\sqrt{3}$ to the power of $1$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 (\sqrt{3} \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Raise $\sqrt{3}$ to the power of $1$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 (\sqrt{3} \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 {\sqrt{3}}^{1 + 1}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Add $1$ and $1$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 {\sqrt{3}}^{2}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite ${\sqrt{3}}^{2}$ as $3$ .

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{3}$ as $3^{\frac{1}{2}}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 {(3^{\frac{1}{2}})}^{2}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 \cdot 3^{\frac{1}{2} \cdot 2}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Combine $\frac{1}{2}$ and $2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 \cdot 3^{\frac{2}{2}}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $2$ .

Cancel the common factor.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 \cdot 3^{\frac{2}{2}}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite the expression.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 \cdot 3}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Evaluate the exponent.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 16 \cdot 3}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $16$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{9 + 12 \sqrt{3} + 12 \sqrt{3} + 48}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Add $9$ and $48$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{57 + 12 \sqrt{3} + 12 \sqrt{3}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Add $12 \sqrt{3}$ and $12 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{57 + 24 \sqrt{3}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factor of $57 + 24 \sqrt{3}$ and $9$ .

Factor $3$ out of $57$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 (19) + 24 \sqrt{3}}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $24 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 (19) + 3 (8 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Factor $3$ out of $3 (19) + 3 (8 \sqrt{3})$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 (19 + 8 \sqrt{3})}{9}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factors.

Factor $3$ out of $9$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 (19 + 8 \sqrt{3})}{3 \cdot 3}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Cancel the common factor.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{3 (19 + 8 \sqrt{3})}{3 \cdot 3}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Rewrite the expression.

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 1.2 (\frac{19 + 8 \sqrt{3}}{3}) - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $1.2 \frac{19 + 8 \sqrt{3}}{3}$ .

Combine $1.2$ and $\frac{19 + 8 \sqrt{3}}{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + \frac{1.2 (19 + 8 \sqrt{3})}{3} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $1.2$ by $19 + 8 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + \frac{39.42768775}{3} - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Divide $39.42768775$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 13.14256258 - 5.2 (- \frac{3 + 4 \sqrt{3}}{3}) - 6$

Multiply $- 5.2 (- \frac{3 + 4 \sqrt{3}}{3})$ .

Multiply $- 1$ by $- 5.2$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 13.14256258 + 5.2 (\frac{3 + 4 \sqrt{3}}{3}) - 6$

Combine $5.2$ and $\frac{3 + 4 \sqrt{3}}{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 13.14256258 + \frac{5.2 (3 + 4 \sqrt{3})}{3} - 6$

Multiply $5.2$ by $3 + 4 \sqrt{3}$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 13.14256258 + \frac{51.62665679}{3} - 6$

Divide $51.62665679$ by $3$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 14.49800358 + 13.14256258 + 17.20888559 - 6$

Simplify by adding and subtracting.

Add $- 14.49800358$ and $13.14256258$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = - 1.355441 + 17.20888559 - 6$

Add $- 1.355441$ and $17.20888559$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 15.85344459 - 6$

Subtract $6$ from $15.85344459$ .

$f (- \frac{3 + 4 \sqrt{3}}{3}) = 9.85344459$

The final answer is $9.85344459$ .

$y = 9.85344459$

Step 16

These are the local extrema for $f (x) = 0.4 x^{3} + 1.2 x^{2} - 5.2 x - 6$ .

$(- \frac{3 - 4 \sqrt{3}}{3}, - 9.85344459)$ is a local minima

$(- \frac{3 + 4 \sqrt{3}}{3}, 9.85344459)$ is a local maxima

Step 17

Find the Maximum/Minimum Value f(x)=0.4x^3+1.2x^2-5.2x-6

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