Hello,
To solve this function for f(4) we need to plug 4 into f(x) and the result will be our answer. We know that f(x) is
. Plugging in 4 we get 
. Therefore, f(4)=41. Hope this helps!
To solve this function for f(4) we need to plug 4 into f(x) and the result will be our answer. We know that f(x) is