If `cosx=tany ,coty=tanz ,cotz=tanx ,` then the value of `sinx` is (a)`2cos18^0` (b) `cos18^0` (c) `sin18^0` (d) `2sin18^0`

Explanation

cosx=tany

`cos^2x=tan^2y`

`=sec^2y-1`

`=1/cos^2y-1`

`=cot^2z-1`

`1+cos^2x=cot^2z`

`=cos^2z/sin^2z`

`=cos^2z/(1-cos^2z)`

...