# How do you find the vertex and intercepts for #y = - 2x^2 + 8x + 4#?

##### 1 Answer

The x-intercepts are simply the roots of the quadratic,

The y-intercept is simply the constant term,

The vertex is the point at which the slope (gradient) is zero, so differentiate and then solve to find the point

#### Explanation:

I'll use the method that requires calculus. Another answerer may be able to answer using only algebra.

First visualise the curve: the

The x-intercepts occur when

Solve using the quadratic formula or otherwise:

To find the vertex, we know that it is a point where the gradient =

Set this equal to zero:

Solving,

Therefore the coordinates of the vertex are