This is a C Program to calculate the sum of cos(x) series.

This C Program calculates the sum of cos(x) series.

Take input from the user and perform operations as shown in the program below.

Here is source code of the C program to C Program calculates the sum of cos(x) series. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

/* * C program to find the sum of cos(x) series */ #include <stdio.h> #include <math.h> void main() { int n, x1, i, j; float x, sign, cosx, fact; printf("Enter the number of the terms in a series\n"); scanf("%d", &n); printf("Enter the value of x(in degrees)\n"); scanf("%f", &x); x1 = x; /* Degrees to radians */ x = x * (3.142 / 180.0); cosx = 1; sign = -1; for (i = 2; i <= n; i = i + 2) { fact = 1; for (j = 1; j <= i; j++) { fact = fact * j; } cosx = cosx + (pow(x, i) / fact) * sign; sign = sign * (-1); } printf("Sum of the cosine series = %7.2f\n", cosx); printf("The value of cos(%d) using library function = %f\n", x1, cos(x)); }

In this C program, library function defined in <math.h> header file is used to compute mathematical functions. We are reading the number of the terms and the degree value of the series using ‘n’ and ‘x’ variables. To find the sum of cos(x) series, the following formula is used.

Cos(x) = cosx + (pow (x, i) / fact) * sign

$ cc pgm63.c -lm $ a.out Enter the number of the terms in a series 3 Enter the value of x(in degrees) 90 Sum of the cosine series = -0.23 The value of cos(90) using library function = -0.000204

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