Question

If cosA + sin B = m and sin A + cos B = n, prove that 2sin (A+B)=m square+ n square-2

Answer 1

Answer:

proved

Step-by-step explanation:

cosA + sin B = m and sin A + cos B = n,

(cosA + sin B)² = m²

( sin A + cos B )² = n²

cos²A + sin² B + 2 cosA sin B =m²

sin² A + cos² B + 2sin A cos B = n²

2 + 2 sin ( A + B ) = m² + n²

2 sin ( A + B ) = m² + n² - 2