Select Function D and check the Display Options f(x), f (x) and both Show Eq. boxes. If the graph of f(x) has a vertical asymptote x = 3, then what is the equation of the horizontal asymptote of f (x)? Use the interactive figure to find your answer. Use the left and right arrow keys to move along a slider as needed. Click here to launch the interactive figure. The horizontal asymptote of f (x) is described by the equation (Type an equation.)