If A = 60° and B = 30°, verify that : sin (A + B) = sin A cos B + cos A

Q) If A = 60° and B = 30°, verify that : sin (A + B) = sin A cos B + cos A sin B

Ans: Here, let’s calculate the values of LHS & RHS one by one and check if it is verified.

LHS = sin (A + B) = sin (60 + 30) = sin (90) = 1

RHS = sin A cos B + cos A sin B

= sin (60) cos (30) + cos (60) sin(30)

= $(\frac{\sqrt 3}{2})( \frac{\sqrt 3}{2}) + (\frac{1}{2})( \frac{1}{2})$

= $\frac{3}{4} + \frac{1}{4}$

= 1 = LHS

Hence verified !

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