SSC Selection Post 2020 PYQ — Question 57

SSC Selection Post - Higher Secondary Level - 6 Nov 2020 - Shift 3 • Quantitative Aptitude • Q57

If 2cos2θ\theta-5cosθ\theta+2 = 0,0°< θ\theta< 90°, then the value of 1(cosecθ+cotθ)\frac{1}{(cosec\theta +cot\theta)}is:

Show answer & explanation

Correct answer: A

Explanation

The correct answer is Option 1 i.e. √3/3.

Given: 2cos²θ − 5cosθ + 2 = 0

Solve: (2cosθ − 1)(cosθ − 2) = 0
⇒ cosθ = 1/2 ⇒ θ = 60°

Find: 1 / (cotθ + cosecθ)
⇒ cot60° = 1/√3, cosec60° = 2/√3
⇒ Sum = 3/√3 = √3

Final: 1 / √3 = √3/3