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What is cos() in C?
harris910
The cos() function returns the cosine of a number. To be more specific, it returns the cosine of a number in the radian float value.
Figure 1 shows the mathematical representation of the cos() function.
Note:
- The
math.hheader file is required for this function.- This
cos()function only works for right-angled triangles.
Syntax
double cos(double num)
Parameter
This function requires a number that represents an angle in radians as a parameter.
In order to convert degrees to radians, use the following formula:
radians = degrees * ( PI / 180.0 )
Return value
cos() returns the cosine of a number (radians float value) that is sent as a parameter.
Example
#include<stdio.h>
//header file
#include<math.h>
int main() {
//positive number in radians
printf("The cosine of %lf is %lf \n", 2.3, cos(2.3));
// negative number in radians
printf("The cosine of %lf is %lf \n", -2.3, cos(-2.3));
//converting the degrees angle into radians and then applying cos()
// degrees = 90.0
// PI = 3.14159265
// result first converts degrees to radians then apply cos
double result=cos(90.0 * (3.14159265 / 180.0));
printf("The cosine of %lf is %lf \n", 90.0, result);
}RELATED TAGS
c
math
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