SSC CGL 2019 PYQ — Question 70

SSC CGL - 7th June 2019 - Shift 3 • Quantitative Aptitude • Q70

If Tanθ/(1 - Cotθ) + Cotθ/(1 - Tanθ) = 1 + k, then k = ?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is Option 4 i.e. SecθCosecθ

⇒ Tanθ/(1 - Cotθ) + Cotθ/(1 - Tanθ) = 1 + k

⇒ (Sinθ/Cosθ)(1 - Cosθ/Sinθ) + (Cosθ/Sinθ)/(1 - Sinθ/Cosθ)

⇒ (Sinθ/Cosθ)(Sinθ - Cosθ/Sinθ) - (Cosθ/Sinθ)/((Sinθ - Cosθ)/Cosθ)

⇒ Sin2θ/(Cosθ(Sinθ - Cosθ)) - Cos2θ/(Sinθ(Sinθ - Cosθ))

⇒ (Sin3θ - Cos3θ)/(SinθCosθ(Sinθ - Cosθ))

⇒ ((Sinθ - Cosθ)(Sin2 + Cos2 + SinθCosθ)/(SinθCosθ(Sinθ - Cosθ))

⇒ (1 + SinθCosθ)/SinθCosθ

⇒ 1 + SecθCosecθ

⇒ k = SecθCosecθ