A comprehensive graph of a logarithmic function should show all intercepts and the vertical asymptote. A standard window shows the intercepts, but the asymptotic behavior of the graph is not evident (the graph appears to "terminate" in quadrant three). This function has a vertical asymptote at x = -2, and the graph should continue upward indefinitely along the right side of this asymptote.

As with rational functions, the calculator has a difficult time properly displaying vertical asymptotic behavior. We can try to improve the graph a bit, but ultimately we must have an understanding of logarithmic functions to be able to correctly "interpret" what the calculator shows us.