Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If cosec θ - cot θ = \(\frac{7}{2}\), then value of cos θ = ?

Options:

\(\frac{45}{53}\)

\(\frac{28}{53}\)

\(\frac{53}{45}\)

\(\frac{53}{28}\)

Correct Answer:

\(\frac{45}{53}\)

Explanation:

If cosec θ - cot θ = \(x\), then cosec θ + cot θ  = \(\frac{1}{x}\)

ATQ,

⇒ cosec θ - cot θ = \(\frac{7}{2}\)    ..........(i)

⇒ cosec θ + cot θ  = \(\frac{2}{7}\)    ..........(ii)

(i) + (ii)

⇒ 2 cosec θ = \(\frac{7}{2}\) + \(\frac{2}{7}\) = \(\frac{49 + 4}{14}\) = \(\frac{53}{14}\)

⇒ cosec θ= \(\frac{53 (H)}{28 (P)}\)

H2 = P2 + B2  ⇒ (53)2 = (28)2 + B2

⇒ B = 45

Hence,

cos θ = \(\frac{B}{H}\) = \(\frac{45}{53}\)