WRITE A C PROGRAM TO SUM THE SERIES:

/*  WRITE A C PROGRAM TO SUM THE SERIES:

                                               x^2     x^4    x^6

                        COS(x)= 1 - ----- +  ----- - ----- + ...

                                                 2!       4!        6!         

*/

#include<stdio.h>

#include<conio.h>

#include<math.h>

#define PI 3.143

long int fact(int n)  /* To find factorial */

{

            if(n==0)

                        return 1;

            else

                        return(n*fact(n-1));

}

void main()

{

            int i,n,term=1;

            float x,y,sum1,sum2;

            clrscr();

            printf("\n COS Series...");

            printf("\n Enter No. of Terms N [1-12] : ");

            scanf("%ld",&n);

            if(n>=1 && n<=12)

            {

                        printf("\n Enter the Value of 'X' : ");

                        scanf("%f",&y);

                        x=y*(PI/180.00); /* Converting degrees to radians */

                        sum1=1;

                        sum2=0;

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

                        {

                                    if(i%4==0)/* To add positive terms */

                                                sum1+=pow(x,i)/(float)fact(i);

                                    else   /* To add Negative terms */

                                                sum2+=pow(x,i)/(float)fact(i);

                                    term++;

                        }

                        printf("\n Cos(%.2f) = %f",y,sum1-sum2);

            }

            else

                        printf("Wrong entry!!!");

            getch();

}

/*         =====OUT PUT=====

      1. COS Series...

             Enter No. of Terms N [1-12] : 9

             Enter the Value of 'X' : 90

             Cos(90.00) = -0.000700

  

      2.   COS Series...

            Enter No. of Terms N [1-12] : 11

            Enter the Value of 'X' : 0

            Cos(0.00) = 1.000000

      3.   COS Series...

             Enter No. of Terms N [1-12] : 0

            Wrong entry!!!

*/