Question

If f(x) =4x^2 and g(x) =5x, what is g(f(2x))?

Answer 1

f(x) = 4x²

g(x) =5x

first let us find f(2x)

replacing x by 2x in f(x)

f(2x) = 4(2x)²= 4(4x²) =16x²

now we find g(f(2x))

we plug the value of f(2x) which is 16x² in the function g(x)

g(f(2x))= g(16x²) = 5* 16x² =80x²

So g(f(2x)) =80x²