# What is the vertex of y= x^2+4x-1?

Jan 28, 2016

The vertex is graph{x^2 + 4x -1 [-10, 10, -5, 5]} $v \left(- 2 , - 1\right)$

#### Explanation:

Given $f \left(x\right) = y = a {x}^{2} + b x + c \text{ }$ form of the equation
The vertex, $v \left(h , k\right)$
 h = -b/(2a); and k = f(h)
Now $f \left(x\right) = {x}^{2} + 4 x - 1$
h = - 4/2 = -2; f(-2) = -1
Thus $v \left(- 2 , - 1\right)$