If cosec2θ (1 + cos θ) (1 − cos θ) = λ, then find the value of λ.
Given: cosec2θ (1 + cos θ) (1 − cos θ) = λ
To find: λ
Consider cosec2θ (1 + cos θ) (1 − cos θ)
∵ (a – b) (a + b) = a2 – b2
∴ cosec2θ (1 + cos θ) (1 − cos θ) = cosec2 θ (1 – cos2 θ)
Now, as sin2 θ + cos2 θ = 1
⇒ sin2 θ = 1 – cos2 θ
⇒ cosec2θ (1 + cos θ) (1 − cos θ) = cosec2 θ (1 – cos2 θ)
= cosec2 θ sin2 θ
Now, ∵
⇒ cosec2 θ (1 + cos θ) (1 − cos θ) = cosec2 θ (1 – cos2 θ)
= cosec2 θ sin2 θ