Question

Use the following function rule to find f(3).
f(x) =4^x -5
F(3) =

Answer 1

`f(3)=59`

Explanation:

If
`f(x)=4^x-5`

then
`f(3)=4^3-5` (substitute x = 3 into the function)

`\implies f(3)=64-5`

`\implies f(3)=59`

Answer 2

59

Explanation:

To find f(3), substitute 3 for x:

`f(3)=4^3-5\\f(3)=64-5\\f(3)=59`