SOLUTION: if f(x)={{{5x^2}}} and g(x)= square root 2x, what is the value of (f*g)(8) i think i need to substitute f(x) to f and g(x) to g to get: {{{(5x^2)}}} * (square root 2x) (8) but a

Algebra ->  Functions -> SOLUTION: if f(x)={{{5x^2}}} and g(x)= square root 2x, what is the value of (f*g)(8) i think i need to substitute f(x) to f and g(x) to g to get: {{{(5x^2)}}} * (square root 2x) (8) but a      Log On


   



Question 286963: if f(x)=5x%5E2 and g(x)= square root 2x, what is the value of (f*g)(8)
i think i need to substitute f(x) to f and g(x) to g to get:
%285x%5E2%29 * (square root 2x) (8) but after this i dont know what to do

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Substitute g(x) for x in f(x).
f%28x%29=5x%5E2
f%28g%28x%29%29=5%28g%28x%29%29%5E2=5%28sqrt%282x%29%29%5E2=5%282x%29=10x
So then
f%28g%288%29%29=10%288%29=80