If $3cot^2x - 7 cosec^2x + 7 = 0,$ then

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Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If $3cot^2x - 7 cosec^2x + 7 = 0,$ then the value of x( 0 ≤ x ≤ 90°) is :

Options:

30°

0°

90°

60°

Correct Answer:

90°

Explanation:

3 cot²x - 7 cosec²x + 7 = 0

{ cosec²x - cot²x = 1 }

3 (cosec²x - 1 ) - 7 cosec²x + 7 = 0

3cosec²x - 7 cosec²x + 4 = 0

- 4 cosec²x + 4 = 0

cosec x = 1

{ we know, cosec 90º = 1 }

So, x = 90º