If (cos2θ - 1)(2sec2θ) + sec2θ + 2tan2θ = 2, 0° < θ < 90°, then is equal to:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 3.
(cos2θ - 1)(2sec2θ) + sec2θ + 2tan2θ = 2
⇒ (-sin2θ).2sec2θ + sec2θ + 2tan2θ = 2
⇒ -2tan2θ + 1 + tan2θ + 2tan2θ = 2
⇒ tan2θ = 1
⇒ θ = 45°
Now, (secθ + sinθ)/(cosecθ - cosθ)
= (sec45° + sin45°)/(cosec45° - cos45°)
= (√2 + 1/√2)/(√2 - 1/√2)
= (3/√2)/(1/√2)
= 3