Maths Funtions in 'C'

if you want to compute 'LOG,COS,etc' varies mathematics function Than you can use #include<math.h> library of 'C'.
C language provides varies built in functions,for computing mathematics functions like logarithmic, trigonometric functions,etc.
for computing varies function then you have to specify header file #include<math.h> at the top as the header file.

#include<math.h>
Function	Description
cos(x)	Sine of x,x in radians
cos(x)	Cosine of x,x in radians
exp(x)	Exponential function e^x
log(x)	logarithm In(x)
power(x,y)	Power of x to y
ceil(x)	Smallest integer greater than X
floor(x)	Largest integer smaller than x

Lets see all this function by an example

#include<stdio.h>            //header file
#include<math.h>
void main()
{
float sine,cosine,logarathmic,expo;          // declaration of variables
int power,ceils,flor;

sine = sin(90);                   
cosine = cos(90);
logarathmic = log(1.85);
expo = exp(1.23);
power = pow(16,2);
ceils = ceil(10.23);
flor = floor(10.23);


printf(" sine of 90 is %f\n",sine);               //sine function of 90
printf(" cosine of 90 is %f\n",cosine);          // cos function for 90
printf(" log of 1.85 is %f\n",logarathmic);      // log value of 1.85
printf(" e raise to  1.23 is %f\n",expo);       // exponential function for 1.23
printf(" Square  of 16 is %d\n",power);         
printf(" ceil value of 10.23 is %d\n",ceils);   //upper value for 10.23 is 11
printf(" floor values of 10.23 is %d\n",flor);  //lower value for 10.23 is 10



}

Output:

sine of 90 is 0.893997
cosine of 90 is -0.448074
log of 1.85 is 0.615186
e raise to 1.23 is 3.421230
Square of 16 is 256
ceil value of 10.23 is 11
floor values of 10.23 is 10