Question

write the equation of the quadratic function with roots -10 and -8 and a vertex at (-9,-3).
help please awarding medal.

Answer 1

@whpalmer4

Answer 2

@Mertsj (Moderator)

Answer 3

If -10 is a root, then x+10 is a factor. If -8 is a root, then x+8 is a factor
So we have: y= a(x+10)(x+8)
Plug in the given point and find a

Answer 4

im not sure what to do just plug in -8 ?

Answer 5

What is the given point?

Answer 6

oh um..-10??

Answer 7

Read the problem. In the problem there is a point given.

Answer 8

-9?

Answer 9

Do you know that points have an x coordinate and a y coordinate?
They are usually expressed in the form of an ordered pair.

Answer 10

yea i havent ever done this before so i dont know anything about it

Answer 11

Replace x with -9 and y with -3 and find a
(-9,-3) is an ordered pair. It designates a certain point. The x coordinate of the point is -9. That means go 9 to the left on the x axis. The y coordinate of the point is -3. That means go down 3 from the y axis.

Answer 12

okay so how do i find the equation now

Answer 13

how do i solve for a

Answer 14

Get a by itself.