Parabolas and Stretch Factors

[HorseWhisperz]

Here is the problem:

If a parabola is the graph of the equation

y = a (x-6)[sup:67ow5x6f]2[/sup:67ow5x6f] -17

a. What are the coordinates of the vertex? (6,-17)

Will the vertex change if a changes? No. Yes.

b. What is the value of stretch factor a if the y-intercept is (0,1)?

c. What is the value of stretch factor a if the graph goes through the point (3, -44)?


I figured out a, but I don't have the slightest idea how to do either b or c. If someone could possibly help me, I would greatly appreciate it. Takk!

 

[Aladdin]

a.correct
b.TRY IT , PUT FOR A ANY NUMBER AND THEN PUT A DIFFERENT NUMBER AND SEE HERE
c, to find the y intercept you set x equal 0 and solve:but since you have the y-intercept
1=a(0-6)^2-17
1=36a-17
36a=18
a=18/36=1/2
d.since the parabola passes through the point B(3, -44)?
yB=a(xB-6)^2-17
Solve