If sin2x = cos(2x - 40°) where 2x is

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Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If sin2x = cos(2x - 40°) where 2x is an acute angle find the value of 2x.

Options:

15°

45°

60°

30°

Correct Answer:

60°

Explanation:

We know that if sinA = cosB, then A + B = 90°

ATQ,

sin2x = cos(2x-30°)

⇒ 2x + 2x - 30° = 90°

⇒ 4x = 120°

⇒ 2x = 60°