SOLUTION: find vertex and intercept coordinates of the following a=b^2-6b-16

Algebra ->  Graphs -> SOLUTION: find vertex and intercept coordinates of the following a=b^2-6b-16      Log On


   

Question 143460: find vertex and intercept coordinates of the following
a=b^2-6b-16
Answer by nabla(475) About Me  (Show Source):
You can put this solution on YOUR website!
Let's rewrite it because the symbols are poorly chosen.
y=x^2-6x-16
The vertex of ax^2+bx+c=0 is x=-b/2a.
For this problem we have x=6/2=3, which gives a y-value of 9-18-16=-25. Vertex is (3,-25).

Intercepts:
x-intercepts: 0=x^2-6x-16
Factor:
0=(x-8)(x+2)
Which implies x=8 or x=-2. In point form, (8,0), (-2,0)
y-intercepts:
set x=0
y=-16. In point form, (0,-16).
Here is the graph:
graph%28+300%2C+200%2C+-5%2C+10%2C+-25%2C+25%2C+x%5E2-6x-16+%29
E-mail me at enabla@gmail.com if you have further difficulty.