dunkin77 wrote:2. For which of the following function f is f(x) =f(1-x) for all x.
1.f(x)=1-x
2. f(x)=1-x^2
3.f(x)=x^2-(1-x)^2
4. f(x)=x^2(1-x)^2
5. f(x)=x/(1-x)


Answer is 4 -- can anyone explain pls?

... this has been already answered many times in the forum ...

.. for finding the answer ... replace x by (1-x) in the choices and the eqn shuld not change .. replace x by (1-x) in 4 .. and u get (1-x)^2(1-(1-x))^2 .. which is equal to (1-x)^2x^2 .. which is the same as x^2(1-x)^2 .. hence the answer ...