If the image of function f (x) = (1-ax) / (1 + ax) (x is not equal to 1 / a) is symmetric with respect to y = x, then what is a?

If the image of function f (x) = (1-ax) / (1 + ax) (x is not equal to 1 / a) is symmetric with respect to y = x, then what is a?


First of all, it is difficult to determine if the following question is y = (1-ax) / (1 + ax) without clear brackets. Secondly, it is necessary to make clear that the image of the original function and the inverse function is symmetrical about the straight line y = x, so the original function of this function is equal to the inverse function. Find the inverse function: y = (1-ax) / (1 + ax) (1 + ax) y = 1-ax, y + AX = 1-ax, ax + AX = 1



If the image of function f (x) = ax + 2 / X-1 is symmetric with respect to the line y = x, then a=


y=(ax+2)/(x-1)
xy-y=ax+2
(y-a)x=y+2(1)
Because it's symmetric about y = X
that
x=(ay+2)/(y-1)
xy-x=ay+2
(y-1)x=ay+2(2)
According to (1) (2)
So a = 1