If lies in the first quadrant, then the value of is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. .
(secθ - tanθ) / (secθ + tanθ) = 1/9
⇒ (1/cosθ - sinθ/cosθ)/(1/cosθ + sinθ/cosθ) = 1/9
⇒ (1 - sinθ)/(1 + sinθ) = 1/9
⇒ 9 - 9sinθ = 1 + sinθ
⇒ 10sinθ = 8
⇒ sinθ = 8/10 = 4/5
⇒ cos2θ = 1 - sin2θ = 1 - (4/5)2 = 1 - 16/25 = 9/25
⇒ cosθ = 3/5
⇒ tanθ = sinθ/cosθ = (4/5)/(3/5) = 4/3
Now, (sinθ - tan2θ)/(sinθ + tan2θ) = [4/5 - (4/3)2]/[4/5 + (4/3)2]
= (4/5 - 16/9)/(4/5 + 16/9)
= (-44/45)/(116/45)
= -11/29
Therefore, the value of the given expression is -11/29.