how to plot a graph in excel and find its derivative

If not, try the other option: ‘Save this file to disk’, then run Maths Helper Plus and choose the ‘Open’ command from the ‘File’ menu. If you choose ‘Open this file from its current location’, then Maths Helper Plus should open the document immediately. You can use this to practice the steps described below, and as a starting point for solving your own problems.įile name: ‘Derivative graph.mhp’ File size: 3kb This works even if you don’t know how to calculate the derivative using algebra.ĭownload the free support file… We have created a Maths Helper Plus document containing the completed example from this topic. Here are some brief observations from the graph above: Original function: y = 0.5x² – x – 1.5įor ‘x’ values less than x=1, the original function (blue) is decreasing left to right, so all tangent lines will have a negative gradient.įor ‘x’ values less than x=1, the derived function (red) is negative.Īt x = 1, the original function has a turning point where the gradient is zero.įor ‘x’ values greater than zero, the original function is increasing left to right, so all tangent lines will have a positive gradient.įor ‘x’ values greater than x = 1, the derived function is positive.Īlso, the derived function ‘x – 1’ is a straight line, which indicates that the gradient of the original function increases at a constant rate as ‘x’ increases.įor any function that can be graphed in Maths Helper Plus, a derivative graph can be calculated and plotted automatically. Using the rules of calculus, the derived function is:įor any ‘x’ value, the ‘y’ value of the derived function equals the gradient of a tangent to the original function at that point. The following graph shows the original function (blue) and its derivative (red) plotted together:Ĭonsider the function plotted in blue above: The ‘derivative’ or ‘derived function’ evaluates to the gradient of the original function at any given ‘x’ value.ĭerivative graphs can tell you a lot about a function. How to plot a graph of the derivative of a function.

How to plot a graph in excel and find its derivative