Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If tanα + sinβ = m

cotα + cosecβ = n, α ≠ β, then

find the value of cosec2β (\(\frac{m}{n}\))2 + 4.

Options:

sec2α + cot2β

cos2β + sec2α

tan2α

tan2β

Correct Answer:

sec2α + cot2β

Explanation:

Put α = 45°, β = 30°

[∵ Two equations and 4 variables are given, put 2 of them any thing]

⇒ tanα + sinβ = m

m = 1 + \(\frac{1}{2}\) = \(\frac{3}{2}\)

⇒ cotα + cosecβ = n

n = 1 + 2 = 3

Put in find out

⇒ cosec2β (\(\frac{m}{n}\))2 + 4

⇒ (2)2 × \(\frac{1}{4}\) + 4 = 5

Now check options and satisfy.

From option A:

⇒ sec2α + cot2β = (\(\sqrt {2}\))2 + (\(\sqrt {3}\))2 = 5 satisfied

 sec2α + cot2β is the correct answer.