This C Program Calculates the Value of sin(x). It’s a non-differentiable function. Start at zero, then goes up to 1, then back down to 0. But then, instead of going negative, it will just “reflect” about the x-axis. The derivative is 1 and then -1 for every x such that sin(x) = 0 (i.e. 0, 180, 360, 540, 720 …).

Here is source code of the C program to Calculate the Value of sin(x). The C program is successfully compiled and run on a Linux system. The program output is also shown below.

`/*`

`* C program to find the value of sin(x) using the series`

`* up to the given accuracy (without using user defined function)`

`* also print sin(x) using library function.`

`*/`

`#include <stdio.h>`

`#include <math.h>`

`#include <stdlib.h>`

void main()

`{`

int n, x1;

float accuracy, term, denominator, x, sinx, sinval;

printf("Enter the value of x (in degrees) \n");

scanf("%f", &x);

x1 = x;

`/* Converting degrees to radians */`

x = x * (3.142 / 180.0);

sinval = sin(x);

printf("Enter the accuracy for the result \n");

scanf("%f", &accuracy);

term = x;

sinx = term;

n = 1;

`do`

`{`

denominator = 2 * n * (2 * n + 1);

term = -term * x * x / denominator;

sinx = sinx + term;

n = n + 1;

} while (accuracy <= fabs(sinval - sinx));

printf("Sum of the sine series = %f \n", sinx);

printf("Using Library function sin(%d) = %f\n", x1, sin(x));

`}`

$ cc pgm14.c -lm $ a.out Enter the value of x (in degrees) 60 Enter the accuracy for the result 0.86602540378443864676372317075294 Sum of the sine series = 0.855862 Using Library function sin(60) = 0.866093 $ a.out Enter the value of x (in degrees) 45 Enter the accuracy for the result 0.70710678118654752440084436210485 Sum of the sine series = 0.704723 Using Library function sin(45) = 0.707179

**Sanfoundry Global Education & Learning Series – 1000 C Programs.**

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If you wish to look at other example programs on Mathematical Functions, go to C Programming Examples on Mathematical Functions. If you wish to look at programming examples on all topics, go to C Programming Examples.