Q. 11

If sin (A + B) = cos (A – B) = , fins A and B.

Answer :

Given :

Sin(A+B) = sin (60 o)

On equating both the sides, we get

A + B = 60 o …(1)


cos(A B) = cos (30 o)

On equating both the sides, we get

A – B = 30 o …(2)

On Adding Eq. (1) and (2), we get

2A = 90 o

A = 45 o

Now, Putting the value of A in Eq.(1), we get

45 o + B =60 o

B = 15 o

Hence, A = 45 o and B = 15 o

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