SSC CGL 2020 PYQ — Question 60

SSC CGL - 5th March 2020 Shift 3 • Quantitative Aptitude • Q60

If tanθ - cotθ = cosecθ, 0o < θ < 90o, then what is the value of (2tanθ - cosθ)/(√(3)cotθ + secθ) ?

Show answer & explanation

Correct answer: C

Explanation

The correct answer is Option 3 i.e. (4√3 - 1)/(6).

Understanding/Application

tanθ - cotθ = cosecθ

tanθ - 1/tanθ = cosecθ

tan2θ - 1= tanθcosecθ

sec2θ - 1 - 1 = secθ

sec2θ - secθ - 2 = 0

sec2θ - 2secθ + secθ - 2 = 0

secθ(secθ - 2) + 1(secθ - 2) = 0

(secθ + 1) (secθ - 2) = 0

From,  00 < θ < 900

secθ = 2

cosθ = 1/2

θ = 600

(2tanθ - cosθ)/(√(3)cotθ + secθ)

= (2tan60 - cos60)/(√(3)cot60 + sec60)

= (2√3 - 1/2)/(√3 × 1/√3 + 2)

= (4√3 - 1)/6