These two functions are symmetric about x=0.5.
In order to clarify the independent variable, suppose that the independent variable of the function y=f( 1-x) is x 1 and the independent variable of y=fx is x2, then 1-x 1=x2 is (x 1+x2)/2=0.5.
Difficulties: How to determine the point M? Because the side lengths of the left right-angled triangle are 3, 4 and 5 respectivel