Saved Bookmarks
| 1. |
Prove that : \(\frac{1}{cosec θ- cot θ}\) = (cosecθ + cotθ). |
|
Answer» L.H.S = \(\frac{1}{cosec θ+ cot θ}\) = \(\frac{cosec\theta+cot\theta}{(cosecθ − cotθ)(cosecθ + cotθ)}\) (By multiplying numerator and denominator by cosecθ + cotθ) = \(\frac{cosecθ + cotθ}{cosec^2θ − cot^2θ}\) (∵ (a+b)(a–b) = a2 − b2 ) = \(\frac{cosecθ + cotθ }{1}\) = cosecθ + cotθ = R.H.S. (∵ cosec2θ = 1 + cot2θ ⇒ cosec2θ − cot2θ = 1) Hence proved |
|