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Math Library Functions

Perform common mathematical calculations.

Include the math header file by using the preprocessor directive #include <math.h> when using functions in the math library.

If multiple arguments, use comma-separated list.

printf( "%.2f", sqrt( 900.0 ) );

Calls function sqrt, which returns the square root of its argument

Arguments may be constants, variables, or expressions.

Function	Description	Example
abs(x)	Return absolute value of integer parameter	n=abs(23) = 23 m=abs(-11) = 11
atof(str)	Convert string to double
ceil(x)	Return the smallest integer that is greater or equal to x	ceil (2.3) = 3.0 ceil (3.8) = 4.0 ceil (-2.3) =-2.0 ceil (-3.8) =-3.0
cos(x)	Calculate cosine, Angle expressed in radians (180 degrees = PI radians).	*cos(453.14/180) = .707**
exp(x)	Calculate exponential	exp(5)=148.413159
fabs	Return absolute value of floating-point	fabs (3.1416) = 3.1416 fabs (-10.6) = 10.6
floor	Round down value	floor (2.3) = 2.0 floor (3.8) = 3.0 floor (-2.3)=-3.0 floor (-3.8)=-4.0
fmod	Return remainder of floating point division	fmod (5.3,2) = 1.300000 fmod (18.5,4.2) = 1.700000
labs	Return absolute value of long integer parameter	labs(100000)=100000 labs(-123456)=123456
log	Calculate natural logarithm	log (5.5)=1.704748
log10	Calculate logarithm base 10	log10 (param)= 3.000000
modf(x,i)	Spli floating-point value into fractional and integer parts	double param, fractpart, intpart; param = 3.14159265; fractpart = modf (param , &intpart); Output: intpart = 3.000000 fractpart = 0.141593
pow(x)	Calculate numeric power	pow (7,3)=343.0 pow(2.2,4) = 23.4256
sin(x)	Calculate sine, x= Angle expressed in radians (180 degrees = PI radians).	*sin (453.14/180);=.707**
sqrt(x)	Calculate square root	sqrt(1024.0)=32.0
tan	Calculate tangent	*tan (603.14/180)=1.7**

/* Testing the math library functions */
#include <stdio.h>
#include <math.h>

int main()
{
printf( "sqrt(%.1f) = %.1f\n", 900.0, sqrt( 900.0 ) );
printf( "sqrt(%.1f) = %.1f\n", 9.0, sqrt( 9.0 ) );
printf( "exp(%.1f) = %f\n", 1.0, exp( 1.0 ) );
printf( "exp(%.1f) = %f\n", 2.0, exp( 2.0 ) );
printf( "log(%f) = %.1f\n", 2.718282, log( 2.718282 ) );
printf( "log(%f) = %.1f\n", 7.389056, log( 7.389056 ) );
printf( "log10(%.1f) = %.1f\n", 1.0, log10( 1.0 ) );
printf( "log10(%.1f) = %.1f\n", 10.0, log10( 10.0 ) );
printf( "log10(%.1f) = %.1f\n", 100.0, log10( 100.0 ) );
printf( "fabs(%.1f) = %.1f\n", 13.5, fabs( 13.5 ) );
printf( "fabs(%.1f) = %.1f\n", 0.0, fabs( 0.0 ) );
printf( "fabs(%.1f) = %.1f\n", -13.5, fabs( -13.5 ) );
printf( "ceil(%.1f) = %.1f\n", 9.2, ceil( 9.2 ) );
printf( "ceil(%.1f) = %.1f\n", -9.8, ceil( -9.8 ) );
printf( "floor(%.1f) = %.1f\n", 9.2, floor( 9.2 ) );
printf( "floor(%.1f) = %.1f\n", -9.8, floor( -9.8 ) );
printf( "pow(%.1f, %.1f) = %.1f\n", 2.0, 7.0,
pow( 2.0, 7.0 ) );
printf( "pow(%.1f, %.1f) = %.1f\n", 9.0, 0.5,
pow( 9.0, 0.5 ) );
printf( "fmod(%.3f/%.3f) = %.3f\n",
13.675, 2.333, fmod( 13.675, 2.333 ) );
printf( "sin(%.1f) = %.1f\n", 0.0, sin( 0.0 ) );
printf( "cos(%.1f) = %.1f\n", 0.0, cos( 0.0 ) );
printf( "tan(%.1f) = %.1f\n", 0.0, tan( 0.0 ) );
return 0;
}