# Maclaurin Series of Cosx

In this tutorial we shall derive the series expansion of the trigonometric function cosine by using Maclaurinâ€™s series expansion function.

Consider the function of the form

Using , the given equation function becomes

Now taking the derivatives of the given function and using , we have

Now using Maclaurinâ€™s series expansion function, we have

Putting the values in the above series, we have