If f (x) = (x-a + 1) / (x-a), the symmetry center of the image of its inverse function is (m, 3), then a =?

If f (x) = (x-a + 1) / (x-a), the symmetry center of the image of its inverse function is (m, 3), then a =?

Inverse function and function are symmetric with respect to y = x, so the center of symmetry must also be symmetric with respect to y = X
So let the center of symmetry of the function be (x, y)
The midpoint of the line between the two symmetrical centers must be on the line y = X
And this line must be perpendicular to y = X
So (x + m) / 2 = (3 + y) / 2
（Y-3)/(x-m)=-1
x=3,y=m
Because f (x) = 1 + 1 / (x-a)
So the center of symmetry is (a, 1)
So a = 3, M = 1