If cos(40° + x) = sin 30°, then the value of x is:
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Correct answer: B
Explanation
The correct answer is option 2 i.e. 20°.
Given, cos(40° + x) = sin 30°
When cosx = siny, then x and y are complementary angles.
According to the given question,
40° + x + 30° = 90°
⇒ x = 90° - 70°
⇒ x = 20°