Cosine Series

The computation of the Cosine Series 

can be done based on the SineSeries.java program in the post below with some minor changes (still assuming that CosineSeries.java is also in the same package where SineSeries.java is). Here we compute the value of the series at x = 45°, which is π/4 in radian measure.

We first define a class called CosineSeriesSummation for summing the series upto a specified number of terms as below:

Next we invoke the method defined above in the CosineSeries class which contains the main() method as:

The output of the program is as:

  The sum of the Cosine Series at x = 0.7853981633974483 upto the    

  first 20 terms is 0.7071067811865475

  Using the cos() method of the java.lang.Math class, the value 

  of the Cosine Function at x = 0.7853981633974483 is 0.7071067811865476