TRIGONOMETRIC FUNCTIONS Basic Graphs (Page 7 of 14)

Because the tangent function is undefined at odd multiples of π/2 (when the value of the cosine function is zero), the graph consists of separate branches with breaks at these values. These branches are separated by vertical asymptotes. Since we are currently graphing in connected mode, the calculator has joined the branches resulting in the vertical line segments drawn where the asymptotes would be. Sometimes this can be an advantage, because they can help you to visualize where the asymptotes are. Regardless, it is important to understand that these line segments are NOT part of the graph of the tangent function!

One way to try to avoid these line segments is to modify the window settings. If we can create a window so that the positions of the vertical asymptotes correspond to pixel coordinates, the "false connections" will not be drawn. This can be nearly impossible though when the asymptotes occur at awkward values such as π/2. A second method to remove the false connections is to graph the function in DOT style. This is accomplished using the style setting on the function editor page.

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