Question

If sin (A - B) = sin A cos B and cos (A - B) = cos A cos B + sin A sin B, find the values of sin 15 and cos 15 .

Answer 1

Step-by-step explanation:

sin15°

sin(45-30°)

sin45°cos30° -cos45°sin30°

=1/√2 × √3/2 - 1/√2 ×1/2

=√3/2√2 - 1/2√2

=√3-1/2√2

cos15°

cos(45°-30°)

use identity of cos(A-B) and solve......