can anyone prove this. i spent ages on it and still can't get it
sinx + 1+ cosx = 2cosecx
Prove this identity Watch
- Thread Starter
Last edited by paul10; 28-11-2010 at 12:11.
- 28-11-2010 12:06
- 28-11-2010 12:40
- Multiply throughout by sin x and 1 + cos x
- expand the (1 + cos x)^2 term
- use the fundamental pythagorean identity to equate sin^2 x + cos^2 x =1
- factorize the numerator of: 2 + 2cos x
- cancel the remaining (1 + cos x) terms
- deduce that the expression: 2/sin x = 2 cosec x.