When you have f(3), that means X is equal to 3.
The problem states if x <-3 then f(x) would be -2.
If x is between -1 and -3, then f(x) would be 4x.
If x is greater than -1, f(x) would be x^2.
3 is greater then -1, so f(3) would be x^2, now replace x with 3 to get 3^2, which equals 9.
f(3) = 9