Indefinite Integral problem

Question

Hello I need some help with this problem because I've already tried solving and putting -3cos(x) + 15ln|sec(x)| for my answer and -3cos(x) - 15ln|cos(x)| but my WebWork won't accept it because it says my answer is not the most general solution

This is the problem:

1. Evaluate the indefinite integral, ∫ (3sin(x) + 15tan(x)) dx

Answer 1

I think WeBWork is looking for that +C :-) don't forget your friendly constants!

-Patrick