# What is the vertex form of y=4x^2 + 8x − 19 ?

Nov 23, 2017

$\left(- 1 , - 23\right)$

#### Explanation:

The vertex equation is:
${x}_{v} = \frac{- b}{2 a}$

for these function,
${x}_{v} = \frac{- 8}{2 \cdot 4} = - 1$

now we substitute $x$ by $- 1$ in the function equation,
f(-1)=4·(-1)^2+8·(-1)-19=-23

so the vertex is point $\left(- 1 , - 23\right)$.