SSC CGL 2022 PYQ — Question 72

SSC CGL - 01 Dec 2022 - Shift 4 • Quantitative Aptitude • Q72

If tan2θ = 1 – a2, then the value of secθ + tan3θ cosecθ is.

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. (2−a2)32{(2 - {{\mathop{\rm a}\nolimits} ^2})^{\frac{3}{2}}}

Calculations:

⇒ tan2θ = 1 – a2

⇒ sec2θ - 1 = 1 - a2

⇒ 2 - a2 = sec2θ

⇒ sec θ = (2 - a2)1/2

Now solving the following value, we get

⇒ secθ + tan3θ cosecθ

⇒ secθ + tan θ.tan2θ.cosec θ

⇒ secθ  + (sinθ/cosθ).tan2θ.(1/sinθ)

⇒ secθ + secθ.tan2θ

⇒ secθ(1 + 1 - a2)

⇒ (2 - a2)1/2 (2 - a2)

⇒ (2 - a2)3/2