Program to calculate the cosine series

Program:

#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
    int i, n;
    float x, val, sum = 1, t = 1;
    clrscr();
    printf("Enter the value for x : ");
    scanf("%f", &x);
    printf("\nEnter the value for n : ");
    scanf("%d", &n);
    val = x;
    x = x * 3.14159 / 180;
    for(i = 1 ; i < n + 1 ; i++)
    {
        t = t * pow((double) (-1), (double) (2 * i - 1)) * x * x / (2 * i * (2 * i - 1));
        sum = sum + t;
    }
    printf("\nCosine value of %f is : %8.4f", val, sum);
    getch();
}

Output:

Enter the value for x : 60
Enter the value for n : 20
Cosine value of 60.000000 is : 0.5000