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COS Function in C

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The C cos Function is a C programming Math Library Function, which is used to calculate the Trigonometry Cosine value for the specified expression. The syntax of the cos in C Programming is

double cos(double number);

TIP : Please refer ACOS Function article to calculate the Arc Cosine of specified expression.

The COS function in C will return the value between -1 and 1. Before we get into to the syntax, Let us see the mathematical formula behind this C Trigonometry Cosine function:

cos(x) = Length of the Adjacent Side / Length of the Hypotenuse

COS Function in C Example
The cos Function in math library allows you to find the trigonometry Cosine for the specified values.
    
This program, ask the user to enter his/her own value, and then it will find the cosine value of the user specified one
/* Example for COS Function in C Programming */

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

int main()
{
  double cosValue, number;
  printf(" Please Enter the Value to calculate Cosine :  ");
  scanf("%lf", &number);
  
  cosValue = cos(number);
  
  printf("\n Cosine value of %lf = %f ", number, cosValue);
  
  return 0;
}
OUTPUT
COS Function in C Programming 1
C COSINE Function Example 2
In this c cosine function example, we are allowing the user to enter the value in degrees, and then we are converting the degrees to Radians. And finally, we are finding the cosine value of the radian
/* Example for COS Function in C Programming */

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

#define PI 3.14
int main()
{
  double cosValue, radianVal, degreeVal;
  printf(" Please Enter an Angle in degrees :  ");
  scanf("%lf", &degreeVal);
  
  // Convert Dgree Value to Radian 
  radianVal = degreeVal * (PI/180);
  cosValue = cos(radianVal);
  
  printf("\n Cosine value of %f = %f ", degreeVal, cosValue);
  
  return 0;
}
OUTPUT
COS Function in C Programming 2