### Home > A2C > Chapter 9 > Lesson 9.1.3 > Problem9-56

9-56.

What is the stretch factor (the value of a) for the equation of the graph in part (c) of problem 9-47? Write the exact equation of the function.

Using the equation that you found before, what value of y did you get for x = 0?
What do you need to multiply that by to get the appropriate value?

The stretch factor is $2$.
The equation is$y = −2\left(x + 2\right)^{2}\left(x − 1\right)$.