If sin x = cos(x + 20°), then what is the value of x?
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Correct answer: A
Explanation
The correct answer is option 1 i.e. 35°.
sin x = cos(x + 20°)
⇒ sin x = sin(90° – x – 20°)
⇒ sin x = sin(70° – x)
⇒ x = 70° – x
⇒ 2x = 70°
⇒ x = 35°