Question

Question 1-2

The functions j(x) = 2(x + 3)² — 10 and k(x) = 2x² + 12x + c are equivalent.

What is the value of c?

Answer 1

c = 18

Explanation:

expand the factor in j(x) and compare like terms with k(x)

j(x) = 2(x + 3)² ← expand factor using FOIL

= 2(x² + 6x + 9) ← distribute parenthesis by 2

= 2x² + 12x + 18

compare to k(x) = 2x² + 12x + c

the 2 expressions are equivalent when c = 18