SSC Selection Post 2022 PYQ — Question 74

SSC Selection Post - Graduation Level 2022 - 14 March 2022 - Shift 3 • Quantitative Aptitude • Q74

If 7 cos2θ + 5 sin2θ - 6 = 0, (0° <  θ < 90°), then what is the value of cosecθ+cotθcosecθ−cotθ\sqrt{{cosec θ+cot θ}\over{cosec θ-cot θ}}?

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. 2\sqrt2 + 1.

7cos2θ + 5sin2θ - 6 = 0 (0° < θ < 90°)

⇒ 7(1 - sin2θ) + 5sin2θ - 6 = 0

⇒ 7 - 7sin2θ + 5sin2θ - 6 = 0

⇒ sin2θ = 1/2

⇒ sinθ = 1/√2

⇒ θ = 45°

Now, cosecθ+cotθcosecθ−cotθ\sqrt{{cosec θ+cot θ}\over{cosec θ-cot θ}}

= √[(√2 + 1)/(√2 - 1)]

= √[(√2 + 1)2]

= √2 + 1