SSC CGL 2020 PYQ — Question 38

SSC CGL Tier II - Quant - 15 Nov 2020 • Quantitative Aptitude • Q38

The value of is (2sin238° - sec252° + cos64° sin26º+sin264º)/tan223º+cot223º-sec267º-cosec267º):

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. −32\frac{-3}{2}

Concept

sin(90° - θ) = cosθ 

tan(90° - θ) = cotθ 

cot(90° - θ) = tanθ 

sin2θ + cos2θ = 1

cosec2θ - cot2θ = 1

sec2θ - tan2θ = 1

Application

[2sin2(90° - 52°)sec252° + cos64° sin(90° - 64°) + sin264°}/{tan2(90° - 67°) - cosec267° + cot2(90° - 67°) - sec267°]

[2cos252° sec252° + cos64° cos64° + sin264°}/{cot267° - cosec267° + tan267° - sec267°]

[2 + (cos264° + sin264°)}/{ - (cosec267° - cot267°) - (sec267° - tan267°)]

We know that, sin2θ + cos2θ = 1, cosec2θ - cot2θ = 1 and sec2θ - tan2θ = 1

(2 + 1)/(-1 - 1)

-3 / 2