I am sure you meant:
f(x) = (x+1)/(x-1)
or
y = (x+1)/(x-1)
f(y) = ( (x+1)/(x-1) + 1) / ( (x+1)/(x-1) - 1)
multiply top and bottom by x-1
f(y) = ( x+1 + x-1) / ( x+1 - (x-1) )
= 2x/2
= x
If f(x)= x+1/x-1 show that x=f(y)
1 answer