Question

Consider the quadratic function that has x-intercepts of -1 and 7 and passes through the point (-2,-20). What is the

value of a in the factored form of this function?

Answer 1

a = -20/9.

Explanation:

We can write it as

f(x) = a(x - 7)(x + 1)

When x = -2 and y = -20 (at the point(-2, -20):

-20 = a(-2 -7)(-2 + 1)

-20 = -9*-1 a

9a = -20

a = -20/9.