Find the derivative of the function using the Quotient Rule. Set the derivative equal to zero to find the critical x value(s). When the derivative is equal to zero the tangent line will be horizontal to the graph of the function.
Substitute the critical value(s) for x into the f(x) function to determine the point(s) at which the the graph of the function has a horizontal tangent line.
x=0 is not a critical value because f(0) is undefined.
The graph of the function has a horizontal tangent line at the point (1, 1).