Find the Vertex y=2x^2-9x+2

$y = 2 x^{2} - 9 x + 2$

Step 1

Rewrite the equation in vertex form.

Complete the square for $2 x^{2} - 9 x + 2$ .

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

$a = 2$

$b = - 9$

$c = 2$

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 $d = \frac{b}{2 a}$ .

$d = \frac{- 9}{2 \cdot 2}$

Simplify the right side.

Multiply $2$ by $2$ .

$d = \frac{- 9}{4}$

Move the negative in front of the fraction.

$d = - \frac{9}{4}$

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 $e = c - \frac{b^{2}}{4 a}$ .

$e = 2 - \frac{{(- 9)}^{2}}{4 \cdot 2}$

Simplify the right side.

Simplify each term.

Raise $- 9$ to the power of $2$ .

$e = 2 - \frac{81}{4 \cdot 2}$

Multiply $4$ by $2$ .

$e = 2 - \frac{81}{8}$

To write $2$ as a fraction with a common denominator, multiply by $\frac{8}{8}$ .

$e = 2 \cdot \frac{8}{8} - \frac{81}{8}$

Combine $2$ and $\frac{8}{8}$ .

$e = \frac{2 \cdot 8}{8} - \frac{81}{8}$

Combine the numerators over the common denominator.

$e = \frac{2 \cdot 8 - 81}{8}$

Simplify the numerator.

Multiply $2$ by $8$ .

$e = \frac{16 - 81}{8}$

Subtract $81$ from $16$ .

$e = \frac{- 65}{8}$

Move the negative in front of the fraction.

$e = - \frac{65}{8}$

Substitute the values of $a$ , $d$ , and $e$ into the vertex form $2 {(x - \frac{9}{4})}^{2} - \frac{65}{8}$ .

$2 {(x - \frac{9}{4})}^{2} - \frac{65}{8}$

Set $y$ equal to the new right side.

$y = 2 {(x - \frac{9}{4})}^{2} - \frac{65}{8}$

Step 2

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

$a = 2$

$h = \frac{9}{4}$

$k = - \frac{65}{8}$

Step 3

Find the vertex $(h, k)$ .

$(\frac{9}{4}, - \frac{65}{8})$

Step 4

Find the Vertex y=2x^2-9x+2

Related Questions

Support LCMGCF.com by disabling your adblocker.