SSC CHSL 2023 PYQ — Question 55

SSC CHSL 2023 - 04 Aug 2023 - Shift 3 • Quantitative Aptitude • Q55

If sec θ\theta + tan θ\theta = √3, then the positive value of sin θ\theta + cos θ\theta is:

Show answer & explanation

Correct answer: A

Explanation

The correct answer is Option 1 i.e.  (1+3)2\frac{(1+\sqrt{3})}{2}.

sec θ\theta + tan θ\theta = √3.....(1) and,

sec θ\theta - tan θ\theta = 1/√3...........(2)

Adding eq 1 and 2

⇒ 2 sec θ\theta = √3 + 1/√3

⇒ 2 sec θ\theta = (3 + 1)/√3

⇒ 2 sec θ\theta = 4/√3

⇒ ​​sec θ\theta = 2/√3

We know that,

⇒ sec θ\theta = H/B = 2/√3

So,

⇒ H2 = B2 + P2

here, H = Hypotaneous, B = Base and, P = Perpendicular

⇒ P2 = 4 - 3

⇒ P = 1

⇒ sin θ\theta = P/H = 1/2

and,

⇒ cos θ\theta = 1/secθ\theta

⇒ cos θ\theta = √3/2

Then, the value of sin θ\theta + cos θ\theta 

⇒ 1/2 + √3/2 = (1 + √3)/2