Question

If `f(x)= 5x^2` and `g(x) = \sqrt 2`, what is the value of `(f \circ g)(8)`?

Answer 1

`(f o g)(8) =f(g(8))=10`

Explanation:

`(f o g)(x) = f(g(x))`, the g function is inside of the f function

`:. (f o g)(8) = f(g(8)) ; g(x)=sqrt2 :. g(8)= sqrt2`

`f(x)=5x^2 :. f(g(8))=f(sqrt2)=5*(sqrt2)^2=10`

`:. (f o g)(8) =f(g(8))=10` [Ans]