If 14 sin2θ + 3 sinθ - 5 = 0, 0° < θ < 90°, then the value of is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. .
14sin2θ + 3sinθ - 5 = 0
⇒ sinθ = [-3 ± √(9 + 280)]/28 = [-3 ± 17]/28
⇒ sinθ = (-3 + 17)/28 = 14/28 = 0.5
⇒ θ = 30°
Now,
= [2 + (1/√3)]/[(2/√3) + √3]
= [(2√3 + 1)/√3]/[(2 + 3)/√3]
= (1 + 2√3)/5