SSC CGL 2021 PYQ — Question 60

SSC CGL - 17 Aug 2021 - Shift 3 • Quantitative Aptitude • Q60

If 7cos2 θ + 5sin2θ - 6 = 0, (0° < θ < 90°) then, what is the value of cosecθ+tanθsecθ−cotθ\sqrt \frac{cosecθ+tan θ}{secθ-cotθ} ?

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Correct answer: A

Explanation

 The correct answer is Option 1 i.e  2+1\sqrt 2+1 .

⇒ 7cos2 θ + 5sin2θ - 6 = 0

⇒ 2cos2 θ + 5cos2 θ + 5sin2θ  = 6

⇒  2cos2 θ = (6 - 5)

⇒  cos2 θ = 1/2

⇒ θ = 45°

⇒ cosecθ+tanθsecθ−cotθ\sqrt \frac{cosecθ+tan θ}{secθ-cotθ} = cosec45°+tan45°sec45°−cot45°\sqrt\frac{cosec45 °+tan 45 °}{sec45 °-cot45 °}
⇒ 2+12−1\sqrt\frac{\sqrt2 + 1}{\sqrt2 - 1} = 2+1\sqrt2 + 1.