Question

Cos60=cos square 30 minus sin square 30= 1 by 2

Answer 1

cos60 = cos²30-sin²30 = 1/2

1/2 = (√3/2)²-(1/2)²

1/2 = 3/4-1/4

1/2 = 3-1/4

1/2 = 2/4

1/2 = 1/2

LHS = RHS.....