totn C Functions

C Language: acos function
(Arc Cosine)

In the C Programming Language, the acos function returns the arc cosine of x.

Syntax

The syntax for the acos function in the C Language is:

double acos(double x);

Parameters or Arguments

x
A value between -1 and 1. A domain error will occur if x is not between -1 and 1.

Returns

The acos function returns the arc cosine of a number represented by x. It will return a value between 0 and π.

Required Header

In the C Language, the required header for the acos function is:

#include <math.h>

Applies To

In the C Language, the acos function can be used in the following versions:

  • ANSI/ISO 9899-1990

acos Example

/* Example using acos by TechOnTheNet.com */

#include <stdio.h>
#include <math.h>

int main(int argc, const char * argv[])
{
    /* Define temporary variables */
    double value;
    double result;

    /* Assign the value we will find the acos of */
    value = 0.5;

    /* Calculate the Arc Cosine of value */
    result = acos(value);

    /* Display the result of the calculation */
    printf("The Arc Cosine of %f is %f\n", value, result);

    return 0;
}

When compiled and run, this application will output:

The Arc Cosine of 0.500000 is 1.047198

Similar Functions

Other C functions that are similar to the acos function: