Explanation:
Since we're having to evaluate the function, we change the x with the numbers given.
To start, we will have f(1/3) x (2)4 (to the power)
we multiply f x (1/3) x 16 (since 4 x 4 would be 16)
which would give 16/3f
If I am wrong please do correct me with how the formula is given, But I hope this helped!!