Maths trig
posted by Stephan pultree .
Use compound angle formulae to express Second harmonic i2= sin2t and the the third harmonic i3=sin3t in terms of the first harmonic sint

sin2t = 2 sint cost
sin3t = sint cos2t + cost sin2t
(cos2t = 1  2sin^2 t) 
Thanks :)

Whats the workings out to get to these answers ? Jw ta