C PROGRAM FOR COSINE SERIES

/*C PROGRAM FOR  COSINE SERIES */

#include<stdio.h>

#include<conio.h>

#include<math.h>

#define pi 3.14

void main()

{

    int n,i,j;

    float x,x1,sum,p,f,k;

    clrscr();

    printf("\n\tCOSINE SERIES");

    printf("\n\t~~~~~~~~~~~~~~~");

    printf("\nEnter the value of n:");

    scanf("%d",&n);

    printf("\nEnter the value for x:");

    scanf("%f",&x);

    x1=x*(pi/180);

    sum=1;

for(i=2;i<=n*2;i+=2)

{

     p=pow(x1,i);

     f=1;

for(j=1;j<i;j++)

{

     f=f*j;

}

     k=1;

     k=k*(-1);

     sum=sum+(p/f)*k;

}

     printf("\n The sum of series %f",sum);

     printf("\n The cosine series:%f",cos(x1));

     getch();

}

OUTPUT:

        COSINE SERIES

        ~~~~~~~~~~~~~~

Enter the value of n: 2

Enter the value for x: 4

 The sum of series: 0.995127

 The cosine series: 0.997567