Question

find angle A and angle B, if cos {A+B} = sin {A-B}=1/2​

Answer 1

Answer:

Cos (A+B) = 1/2

But cos 60° = 1/2

Therefore A+B = 60°

A = 60-B.......(1)

Sin(A-B) = 1/2

But sin 30° = 1/2

Therefore A-B = 30°......(2)

Substituting (1) in (2),

60 - B - B = 30

-2B = - 30

B = 30/2 = 15°

A = 60-15 = 45°

#WMK