# How do you identify the important parts of #y = –2x^2 – 32x – 126# to graph it?

##### 1 Answer

Sep 30, 2015

Graph

#### Explanation:

The important parts to find are:

x-coodinate of vertex and axis of symmetry:

y-coordinate of vertex:

y = f(8) = -2(64) - 32(-8) - 126 = 2

y-intercept --> Make x = 0 --> y = -126

x-intercepts --> Make x = 0, solve y = 0

Roots have same sign, Factor pairs of (63) --> (3, 31)(7, 9). This sum is 16 = b. Then the 2 x-intercepts (real roots) are : 7 and 9

graph{-2x^2 - 32x - 126 [-10, 10, -5, 5]}