If you understand the definition of a mathematical function, a good way to judge it is that any line drawn parallel to the y-axis intersects with the values in the function’s curve only once. The same ...

Grid lines add horizontal and/or vertical lines to your graph that aid in measuring graph values. By default, these grid lines use the color assigned to the "automatic" selection feature, which is ...

The interval between the gridlines in an Excel chart is typically blank, but you can highlight the intervals using an alternating pattern by changing the formatting for the gridlines themselves.