If prove this In this case i substitute but after the solving it become more tough.please help me>>>>>>

Last edited by srirahulan; July 20th 2013 at 10:29 PM.

Follow Math Help Forum on Facebook and Google+

Have you thought to work out ?

after that I cannot arrange what ther ask>>>>>>

Last edited by srirahulan; July 21st 2013 at 12:22 AM.

I don't know why you're substituting tan(x), or ANY other function for that matter. Just take the derivative...