Are you asking a question different to sinAcosB+cosAsinB=sin(A+B) ?
How does this simplify to sin3x:
sinxcos2x + sin2xcosx = sin3x
this is part of parametric equations ch10 in my Calculus textbook. I am not sure if they used a trig identity or pure algebra.
Thanks for the help. You are right about that identity.
I knew the Calculus but it is only the trig and algebra which costs me points on the Calculus exam.
Thanks again. So How do I give you exp points for helping me out so the green balls will increase on your account.