For which of the following functions f is f(x)=f(1-x) for all x?

Chayane

For which of the following functions f is f(x)=f(1-x) forall x?

F(x)=1-x

F(x)=1-X^2

F(x)=x^2-(1-x)^2

F(x)=X^2(1-x)^2

F(x)=x/(1-x)

schighness

选第四个，代入试试就知道了