SOLUTION: A certain polynomial function f(x) of degree 2 has zeroes at -3 and 5, and f(2)= -30. What is the polynomial function f(x)?

Algebra ->  Functions -> SOLUTION: A certain polynomial function f(x) of degree 2 has zeroes at -3 and 5, and f(2)= -30. What is the polynomial function f(x)?      Log On


   



Question 973299: A certain polynomial function f(x) of degree 2 has zeroes at -3 and 5, and f(2)= -30. What is the polynomial function f(x)?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
(x+3)=0 zero at -3
(x-5)=0 zero at 5
(x+3)(x-5)=0 for f(2)=-30, let a be variable to adjust to -30:
a(2+3)(2-5)=-30
a(5)(-3)=-30
a(-15)=-30
a=2
The entire equation:
f%28x%29=%282%29%28x%2B3%29%28x-5%29
f%28x%29=%282x%2B6%29%28x-5%29
f%28x%29=2x%5E2-4x-30