Answers

2015-06-12T19:54:59+05:30
Given that
sin (A – B) = 1/2
⇒ A - B = 30°  (as sin 30° = 1/2)

cos (A + B) = 1/2
⇒ A+B = 60° (as cos 60° = 1/2)

Now solve these two equations to find out A and B.
Add them, 
2A = 90°
⇒ A = 90°/2 = 45
B = 60° - A = 60° - 45° = 15°

So A = 45° and B=15°
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