# How do you find the vertex and intercepts for #y =1/2x^2 +2x - 8#?

##### 1 Answer

Vertex:

y-intercept:

x-intercepts

#### Explanation:

**Finding the vertex**

Notice that our target will be the vertex form

Given

Isolate the terms involving

Modify so the coefficient of

Noting that if

So we will need to add

or

Now we reverse the process to isolate

which is the vertex form with vertex at

**y-intercept**

The y-intercept is the value of

**x-intercepts**

Similarly the x-intercept values are the values of

So we need to solve

or (simplified by multiplying both sides by

Using the quadratic formula (ask if you need this), we can find

graph{(1/2)x^2+2x-8 [-13.55, 11.76, -10.93, 1.73]}