Graphing quadratics

Question

graph -x^2-8x-15 for x values -2 to 4 

b) what is the vertex 

c) what is the x-intercept 

d) what is the y-intercept 

e) factor the expression 

f) what is the equation in vertex form 

Answer 1

                                   Computer Generated Solution
Equation to solve is:

−x2−8x−15=0
The solutions are:

x1=−3x2=−5
Explanation

First we will simplify equation by multiplying both sides with -1 . After multiplying we have the following equation.

x2+8x+15=0
STEP1: Find coefficients a , b and c.

In this example a=1,b=8,c=15

STEP2: Plug in the values for a, b, and c into the quadratic formula

x1,2=−b±b2−4ac−−−−−−−√2a
x1,2=−8±82−4⋅1⋅15−−−−−−−−−−√2⋅1
STEP3: Simplify expression under the square root.

x1,2=−8±4√2
STEP4: Solve for x

x1=−8 + 4√2=−3
x2=−8 − 4√2=−5