if a is the root of the eqn. f(x)=f^--1(x)....then f(x) =x @ x=a....

so we have x + sin (pix) /pi= x...(actually im not being able to make out wat uve written clearly)

or sin(pix)/pi =0....and using this u can get to the soln....but the main funda is as explained in the first line...

jus. given the brief method...

rate if useful...