How to integrate 5·sin(6x)/sin(3x)

[RedBarchetta]

Homework Statement

The integral of 5*(sin(6x)/sin(3x))dx

The Attempt at a Solution

I'm not quite sure what to do with this one. I moved 5 to the left of the integral, but then I'm lost. Apparently I'm rusty on these trig identities.

Could anyone help me get started? Thank you.

 

[jandl]

Look up the double angle formula for sine, wikipedia is good. You should be able to simplify with the bottom some then.