If x = 30°, then prove that

21

If x = 30°, then prove that

sin3x = 3sinx – 4 sin³x

21

If x = 30°, then prove that

21

If x = 30°, then prove that

cos3x = 4 cos³x – 3cosx

22

If A = 60° and B = 30° then prove that