If 2cos2-5cos+2 = 0,0°< < 90°, then the value of is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. √3/3.
Given: 2cos²θ − 5cosθ + 2 = 0
Solve: (2cosθ − 1)(cosθ − 2) = 0
⇒ cosθ = 1/2 ⇒ θ = 60°
Find: 1 / (cotθ + cosecθ)
⇒ cot60° = 1/√3, cosec60° = 2/√3
⇒ Sum = 3/√3 = √3
Final: 1 / √3 = √3/3