C <math.h> Library Function: The C math.h library function defines various mathematical functions and one macro. All the functions available in this library take double as an argument and return double as the result.
Contents
- 1 C math.h Library Function
- 1.1 double floor(double x)
- 1.2 double fabs(double x)
- 1.3 double log(double x)
- 1.4 double log10(double x)
- 1.5 double fmod(double x, double y)
- 1.6 double sqrt(double x)
- 1.7 double pow(double x, double y)
- 1.8 double modf(double x, double *integer)
- 1.9 double exp(double x)
- 1.10 double cos(double x)
- 1.11 double acos(double x)
- 1.12 double tanh(double x)
double ceil(double x)
The C library function double ceil(double x) returns the smallest integer value greater than or equal to x.
Syntax : double ceil(double x)
Example
#include <stdio.h> #include <math.h> int main () { float val1, val2, val3, val4; val1 = 1.6; val2 = 1.2; val3 = -2.8; val4 = -2.3; printf ("value1 = %.1lf\n", ceil(val1)); printf ("value2 = %.1lf\n", ceil(val2)); printf ("value3 = %.1lf\n", ceil(val3)); printf ("value4 = %.1lf\n", ceil(val4)); return(0); }
Output
value1 = 2.0
value2 = 2.0
value3 = -2.0
value4 = -2.0
C math.h Library Function
double floor(double x)
The C library function double floor(double x) returns the largest integer value less than or equal to x.
Syntax : double floor(double x)
Example
#include<stdio.h> #include<math.h> int main() { float val1, val2, val3, val4; val1 = 1.6; val2 = 1.2; val3 = -2.8; val4 = -2.3; printf("Value1 = %.1lf\n", floor(val1)); printf("Value2 = %.1lf\n", floor(val2)); printf("Value3 = %.1lf\n", floor(val3)); printf("Value4 = %.1lf\n", floor(val4)); return(0); }
Output
Value1 = 1.0
Value2 = 1.0
Value3 = -3.0
Value4 = -3.0
double fabs(double x)
The C library function double fabs(double x) returns the absolute value of x.
Syntax : double fabs(double x)
Example
#include<stdio.h> #include<math.h> int main() { int a, b; a = 1234; b = -344; printf("The absolute value of %d is %lf\n", a, fabs(a)); printf("The absolute value of %d is %lf\n", b, fabs(b)); return(0); }
Output
The absolute value of 1234 is 1234.000000
The absolute value of -344 is 344.000000
double log(double x)
The C library function double log(double x) returns the natural logarithm (base-e logarithm) of x.
Syntax : double log(double x)
Example
#include<stdio.h> #include<math.h> int main() { double x, ret; x = 2.7; /*finding log(2.7) */ ret = log(x); printf("log(%lf) = %lf", x, ret); return(0); }
Output
log(2.700000) = 0.993252
double log10(double x)
The C library function double log10(double x) returns the common logarithm (base-10 logarithm) of x.
Syntax : double log10(double x)
Example
#include<stdio.h> #include<math.h> int main() { double x, ret; x = 10000; /* finding value of log1010000 */ ret = log10(x); printf("log10(%lf) = %lf\n", x, ret); return(0); }
Output
log10(10000.000000) = 4.000000
double fmod(double x, double y)
The C library function double fmod(double x, double y) returns the remainder of x divided by y.
Syntax: double fmod(double x, double y)
Example
#include<stdio.h> #include<math.h> int main() { float a, b; int c; a = 8.2; b = 5.7; c = 3; printf("Remainder of %f / %d is %lf\n", a, c, fmod(a, c)); printf("Remainder of %f / %f is %lf\n", a, b, fmod(a, b)); return(0); }
Output
The remainder of 8.200000 / 3 is 2.200000
The remainder of 8.200000 / 5.700000 is 2.500000
double sqrt(double x)
The C library function double sqrt(double x) returns the square root of x.
Syntax : double sqrt(double x)
Example
#include<stdio.h> #include<math.h> int main () { printf("Square root of %lf is %lf\n", 225.0, sqrt(225.0) ); printf("Square root of %lf is %lf\n", 300.0, sqrt(300.0) ); return(0); }
Output
The square root of 225.000000 is 15.000000
The square root of 300.000000 is 17.320508
double pow(double x, double y)
The C library function double pow(double x, double y) returns x raised to the power of y i.e. XY.
Syntax: double pow(double x, double y)
Example
#include<stdio.h> #include<math.h> int main () { printf("Value 8.0 ^ 3 = %lf\n", pow(8.0, 3)); printf("Value 3.05 ^ 1.98 = %lf", pow(3.05, 1.98)); return(0); }
Output
Value 8.0 ^ 3 = 512.000000
Value 3.05 ^ 1.98 = 9.097324
double modf(double x, double *integer)
The C library function double modf(double x, double *integer) returns the fraction component (part after the decimal), and sets integer to the integer component.
Syntax : double modf(double x, double *integer)
Example
#include<stdio.h> #include<math.h> int main() { double x, fractpart, intpart; x = 8.123456; fractpart = modf(x, &intpart); printf("Integral part = %lf\n", intpart); printf("Fraction Part = %lf \n", fractpart); return(0); }
Output
Integral part = 8.000000
Fraction Part = 0.123456
double exp(double x)
The C library function double exp(double x) returns the value of e raised to the xth power.
Syntax : double exp(double x)
Example
#include<stdio.h> #include<math.h> int main () { double x = 0; printf("The exponential value of %lf is %lf\n", x, exp(x)); printf("The exponential value of %lf is %lf\n", x+1, exp(x+1)); printf("The exponential value of %lf is %lf\n", x+2, exp(x+2)); return(0); }
Output
The exponential value of 0.000000 is 1.000000
The exponential value of 1.000000 is 2.718282
The exponential value of 2.000000 is 7.389056
double cos(double x)
The C library function double cos(double x) returns the cosine of a radian angle x.
Syntax : double cos(double x)
Example
#include<stdio.h> #include<math.h> #define PI 3.14159265 int main () { double x, ret, val; x = 60.0; val = PI / 180.0; ret = cos( x*val ); printf("The cosine of %lf is %lf degrees\n", x, ret); x = 90.0; val = PI / 180.0; ret = cos( x*val ); printf("The cosine of %lf is %lf degrees\n", x, ret); return(0); }
Output
The cosine of 60.000000 is 0.500000 degrees
The cosine of 90.000000 is 0.000000 degrees
double acos(double x)
The C library function double acos(double x) returns the arc cosine of x in radians.
Syntax : double acos(double x)
Example
#include<stdio.h> #include<math.h> #define PI 3.14159265 int main() { double x, ret, val; x = 0.9; val = 180.0 / PI; ret = acos(x) * val; printf("The arc cosine of %lf is %lf degrees", x, ret); return(0); }
Output
The arc cosine of 0.900000 is 25.855040 degrees.
double tanh(double x)
The C library function double tanh(double x) returns the hyperbolic tangent of x.
Syntax : double tanh(double x)
Example
#include<stdio.h> #include<math.h> int main() { double x, ret; x = 0.5; ret = tanh(x); printf("The hyperbolic tangent of %lf is %lf degrees", x, ret); return(0); }
Output
The hyperbolic tangent of 0.500000 is 0.462117 degrees