1.

If sin(A + B) = cos(A - B) = \(\frac{\sqrt 3}{2}\) and A and B are acute angle. The measures of angles A and B (in degrees) will be:1. A = 60 and B = 302. A = 45 and B = 153. A = 45 and B = 454. A = 15 and B = 45

Answer» Correct Answer - Option 2 : A = 45 and B = 15

Given:

sin(A + B ) = cos(A - B) = √3/2

Calculation:

sin(A + B) = √3/2

⇒ sin(A + B )= sin60°

⇒  A + B = 60°      ….(i)

And, cos(A - B) = √3/2

⇒ cos(A - B) = cos30°

⇒  A – B = 30°      ….(ii)

Adding (i) and (ii)

We get, 2A = 90°

⇒  A = 45°

Putting in (i)

We get, 

⇒ 45° + B = 60°

⇒  B = 15°

∴ A and B are 45°and 15°

Short trick

sin(A + B )= sin60 

cos(A - B) = cos30°

So, A + B = 60° and A – B = 30°

Takes oprtion he different is 30° and sum is 60° 

So option B and D are satisfy but in option D difference is negative

Then option B is right

A= 45° and B = 15° 



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