The constant term in the equation (the + 1 or ‒ 2) shows the point where the graph crosses the y -axis. This is known as the y -intercept and is represented by the letter c in y = m x + c.

For example, you could show line graphs for temperature and humidity on top of each other. For this purpose, Excel lets you add a series of data to a chart and plot it on a second y-axis.

Functions The graph of y = f (x) where f (x) = x 2 is the same as the graph of y = x 2. Writing equations as functions in the form f (x) is useful when applying translations and reflections to graphs.

Step approximation models provide a simple method of studying mode propagation and mode conversion in planar Y-branch optical waveguides. They are, however, only applicable to small branching angles ...