SSC CPO 2020 PYQ — Question 122

SSC CPO - 25 Nov 2020 - Shift 2 • Quantitative Aptitude • Q122

If cotθ = 1√3\frac{1}{√3} , 0° < θ° < 90°, then the value of 2−sin2θ1−cos2θ\frac{2-sin^2\theta}{1-cos^2\theta} + (cosec2θ - secθ) is:

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Correct answer: C

Explanation

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

cotθ = 1√3\frac{1}{√3} 

cotθ = cot 60°

θ = 60°

Then,

The value of 2−sin2θ1−cos2θ\frac{2-sin^2\theta}{1-cos^2\theta} + (cosec2θ - secθ)

2−sin260°1−cos260°\frac{2-sin^260°}{1-cos^260°} + (cosec260° - sec60°)

⇒ 2−(32)21−(12)2\frac{2-({\sqrt3\over2})^2}{1-({1\over2})^2} + ((23)2({2\over{\sqrt3}})^2 - (2)(2))

⇒ 2−341−14\frac{2-{3\over4}}{1-{1\over4}} + (43{4\over{3}} - 2)

⇒ 8−34−1\frac{8-3}{4-1} + (4 - 6)/3

⇒ 53\frac{5}{3} + −23{-2\over3} = 3/3 = 1