Question

Q 12 + = 1, = 30° and B is an acute angle, then find the value of B.

=>
$\sin(a) + \cos(b) = 1 \\ \sin(30) + \cos(b) = 1 \\ \frac{1}{2} + \cos(b) = 1 \\ \cos(b) =1 - \frac{1}{2} \\ \cos(b) = \frac{1}{2} \\ b = 30 \: degree$
Angle B=30° because cos30 =1/2


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