General solution of `(i) sin^2theta = sin^2alpha; (ii) cos^2 theta = cos^2 alpha (iii) tan^2 t - YouTube
sin theta +sin 2theta +sin 3theta = sin alpha and cos theta + cos 2theta +cos 3theta= cos alpha then theta is equal to 1) alpha/2 2)alpha 3)2alpha 4) alpha/6
Loi de Morrie — Wikipédia
The general solution of the equation sin^2 theta = sin^2 alpha is
Trig 3-5 problem 59 - Find the Sin 2alpha given sin alpha - YouTube