Solve `x^2-2x+1=0` to determine the values of x for which the denominator is 0, so the function would be undefined.
Solve by factoring:
The function `f(x)=(x+1)/(x^2-2x+1)` is undefined for x=1, then there is an asymptote at x=1.
The domain of the function is x>1 and x>1.
Graph of `(x+1)/(x^2-2x+1)` in black and `x^2-2x+1` in red.