Question

sin 2A = 2 sin A is true when A = (A) 0° (B) 30° (C) 45° (D) 60°

Answer 1

Solution: (A) 0^o

Sin 0° = 0 and Sin 2 x 0° = Sin 0° = 0

Sin 30° = ½ But Sin 2 x 30° = Sin 60° is not equal to Sin 30°. The same holds true for sin 45°.