Question

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Sin A + Cos B = 1 and A = 30°
To find: The value of B is an acute angle,then find the value of B...
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Answer 1

sinA + cosB = 1

sin30° + cosB = 1

1/2 + cosB = 1

cosB = 1 - 1/2

cosB = (2 - 1)/2

cosB = 1/2

cosB = cos60° ... cos60° = 1/2

B = 60°

Answer 2

Given:

sin A+ cos B=1

To find:

The value of B

Solution:

By putting A=30°

sin=30°+cos B=1

$\displaystyle \dfrac{1}{2}$+cos B=1

cos B=1-$\displaystyle \dfrac{1}{2}$

cos B= cos 60°

Thus B is equal to 60°