Trig and double angle integration

[banshee43]

Homework Statement

∫sin(t)cos(2t)dt

Homework Equations

cos(2t)=1-2sin^2(t)

The Attempt at a Solution

∫sint(t)(1-2sin^2(t))dt
but where do i go from here? i can't use substitution. or parts?

 

[iRaid]

cos2x can also = 2cos²x-1, if you make it that, then this is a simple u-substitution..
u=cosx

 

[banshee43]

thankyou very much! i just didnt exhaust my formulas..