Question

let the function f be defined by f(x)=x^2+18. if a is a positive number such that f(2a) = 3f(a), what is the value of a?

Answer 1

Hi,

Explanation:

`f(x)=x^2+18\\\\f(2a)=3*f(a)\\\\(2a)^2+18=3(a^2+18)\\\\4a^2+18=3a^2+54\\\\a^2=36\\\\\boxed{a=6}`because a >0