Question

Prove that:
Sin 65° - Sin 25° = √2 sin 20°

Answer 1

Step-by-step explanation:

SinA -SinB= 2Cos(A+B)/2.Sin(A-B)/2

Sin65° -Sin25° = 2cos(65°+25°)sin(20°)

by formula =2Cos45°Sin20°

= 2×1/√2sin20°

=√2sin20°