# How do you find the vertex of a parabola f(x) = -x^2 - 2x?

Mar 18, 2018

The vertex is (-1, 1)

#### Explanation:

The equation is in standard form

Standard form of a parabola:
$f \left(x\right) = a {x}^{2} + b x + c$
$- 1$ would be a and $- 2$ would be b in this equation.

To find the vertex, do $\frac{- b}{2 a} , f \left(- \frac{b}{2 a}\right)$.

$\frac{2}{2 \cdot - 1}$

$\frac{2}{-} 2$

$- 1$

$f \left(- 1\right) = - {\left(- 1\right)}^{2} - 2 \cdot - 1$

$f \left(- 1\right) = - 1 + 2$

$f \left(- 1\right) = 1$

The vertex is (-1, 1)