Excel does not have a built-in feature to directly plot mathematical functions like 1/(x^2+4), but users can graph functions by calculating points in a tabular format. To create a graph, input the function in a cell, referencing another cell for x values. For example, in cell B1, use the formula =1/(A1^2+4) where A1 contains the initial x value. Increment x values in column A (e.g., starting from 0 and increasing by 0.05) by dragging down the fill handle. After calculating corresponding y values in column B, users can plot these columns as a line or scatter graph. This method allows for experimentation with different functions by adjusting the formulas in column A, with the graph updating automatically based on new x values.