Question

A function f(x) has x-intercepts of –3 and –5. What is the constant term in the function? f(x) = x2 + 8x +

Answer 1

15

Explanation:

f(x) = x2 + 8x + 15

Answer 2

15

Explanation:

since the x-intercepts are x = - 3 and x = - 5 then the factors are

(x + 3) and (x + 5), hence

f(x) = a(x + 3)(x + 5) ← a is a multiplier

let a = 1 then

f(x) = (x + 3)(x + 5) ← expand factors

f(x) = x² + 8x + 15 ← 15 is the constant term