Find the Axis of Symmetry y=3x^2-4x+5

$y = 3 x^{2} - 4 x + 5$

Rewrite the equation in vertex form.

Complete the square for $3 x^{2} - 4 x + 5$ .

Use the form $a x^{2} + b x + c$ , to find the values of $a$ , $b$ , and $c$ .

$a = 3$

$b = - 4$

$c = 5$

Consider the vertex form of a parabola.

$a {(x + d)}^{2} + e$

Find the value of $d$ using the formula $d = \frac{b}{2 a}$ .

Substitute the values of $a$ and $b$ into the formula $d = \frac{b}{2 a}$ .

$d = \frac{- 4}{2 \cdot 3}$

Simplify the right side.

Cancel the common factor of $- 4$ and $2$ .

Factor $2$ out of $- 4$ .

$d = \frac{2 \cdot - 2}{2 \cdot 3}$

Cancel the common factors.

Factor $2$ out of $2 \cdot 3$ .

$d = \frac{2 \cdot - 2}{2 (3)}$

Cancel the common factor.

$d = \frac{2 \cdot - 2}{2 \cdot 3}$

Rewrite the expression.

$d = \frac{- 2}{3}$

Move the negative in front of the fraction.

$d = - \frac{2}{3}$

Find the value of $e$ using the formula $e = c - \frac{b^{2}}{4 a}$ .

Substitute the values of $c$ , $b$ and $a$ into the formula $e = c - \frac{b^{2}}{4 a}$ .

$e = 5 - \frac{{(- 4)}^{2}}{4 \cdot 3}$

Simplify the right side.

Cancel the common factor of ${(- 4)}^{2}$ and $4$ .

Rewrite $- 4$ as $- 1 (4)$ .

$e = 5 - \frac{{(- 1 (4))}^{2}}{4 \cdot 3}$

Apply the product rule to $- 1 (4)$ .

$e = 5 - \frac{{(- 1)}^{2} \cdot 4^{2}}{4 \cdot 3}$

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

$e = 5 - \frac{1 \cdot 4^{2}}{4 \cdot 3}$

Multiply $4^{2}$ by $1$ .

$e = 5 - \frac{4^{2}}{4 \cdot 3}$

Factor $4$ out of $4^{2}$ .

$e = 5 - \frac{4 \cdot 4}{4 \cdot 3}$

Cancel the common factors.

Factor $4$ out of $4 \cdot 3$ .

$e = 5 - \frac{4 \cdot 4}{4 (3)}$

Cancel the common factor.

$e = 5 - \frac{4 \cdot 4}{4 \cdot 3}$

Rewrite the expression.

$e = 5 - \frac{4}{3}$

To write $5$ as a fraction with a common denominator, multiply by $\frac{3}{3}$ .

$e = 5 \cdot \frac{3}{3} - \frac{4}{3}$

Combine $5$ and $\frac{3}{3}$ .

$e = \frac{5 \cdot 3}{3} - \frac{4}{3}$

Combine the numerators over the common denominator.

$e = \frac{5 \cdot 3 - 4}{3}$

Simplify the numerator.

Multiply $5$ by $3$ .

$e = \frac{15 - 4}{3}$

Subtract $4$ from $15$ .

$e = \frac{11}{3}$

Substitute the values of $a$ , $d$ , and $e$ into the vertex form $3 {(x - \frac{2}{3})}^{2} + \frac{11}{3}$ .

$3 {(x - \frac{2}{3})}^{2} + \frac{11}{3}$

Set $y$ equal to the new right side.

$y = 3 {(x - \frac{2}{3})}^{2} + \frac{11}{3}$

Use the vertex form, $y = a {(x - h)}^{2} + k$ , to determine the values of $a$ , $h$ , and $k$ .

$a = 3$

$h = \frac{2}{3}$

$k = \frac{11}{3}$

Since the value of $a$ is positive, the parabola opens up.

Opens Up

Find the vertex $(h, k)$ .

$(\frac{2}{3}, \frac{11}{3})$

Find $p$ , the distance from the vertex to the focus.

Find the distance from the vertex to a focus of the parabola by using the following formula.

$\frac{1}{4 a}$

Substitute the value of $a$ into the formula.

$\frac{1}{4 \cdot 3}$

Multiply $4$ by $3$ .

$\frac{1}{12}$

Find the focus.

The focus of a parabola can be found by adding $p$ to the y-coordinate $k$ if the parabola opens up or down.

$(h, k + p)$

Substitute the known values of $h$ , $p$ , and $k$ into the formula and simplify.

$(\frac{2}{3}, \frac{15}{4})$

Find the axis of symmetry by finding the line that passes through the vertex and the focus.

$x = \frac{2}{3}$

Find the Axis of Symmetry y=3x^2-4x+5

Related Questions

Support LCMGCF.com by disabling your adblocker.