math.h in C

The function double acos (double x) in Library C returns the arcos of x (radian value).

Declare acos () function in C

Below is the declaration for acos () function in C:

 double  acos ( double  x ) 

Parameters:

x - This is the actual floating point number in the paragraph [-1, + 1].

Return value:

This function returns the arcos of x, in the segment [0, pi] radian.

For example:

The following program C illustrates how to use the acos () function in C:

 #include #include #define  PI  3.14159265 int  main  () { double  x ,  ret ,  val ;  x  = 0.9 ;  val  = 180.0 /  PI ;  ret  =  acos ( x ) *  val ;  printf ( "Gia tri arccos cua %lf la bang %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

2. The asin () function in C

The double asin (double x) function in Library C returns arcsin of x (radian value).

Declare the function asin () in C

Below is the declaration for the asin () function in C:

 double  asin ( double  x ) 

Parameters:

x - This is the actual floating point number in the paragraph [-1, + 1].

Return value:

This function returns arcsin of x, in the [-pi / 2, + pi / 2] radian segment.

For example:

The following program C illustrates the usage of the asin () function in C:

 #include #include #define  PI  3.14159265 int  main  () { double  x ,  ret ,  val ;  x  = 0.9 ;  val  = 180.0 /  PI ;  ret  =  asin ( x ) *  val ;  printf ( "Gia tri arcsin cua %lf la bang %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

3. The atan () function in C

Double atan (double x) function in C Library returns arctan of x (radian value).

Declaring the function atan () in C

Below is the declaration for the atan () function in C:

 double  atan ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns arctan of x, in the [-pi / 2, + pi / 2] radian.

For example:

The following C program illustrates the use of atan () function in C:

 #include #include #define  PI  3.14159265 int  main  () { double  x ,  ret ,  val ;  x  = 1.0 ;  val  = 180.0 /  PI ;  ret  =  atan  ( x ) *  val ;  printf ( "Gia tri arctan cua %lf la bang %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

4. The function atan2 () in C

Double atan2 (doubly y, double x) in Library C returns arctan of y / x (radian value).

Declare the function atan2 () in C

Here is the declaration for the atan2 () function in C:

 double  atan2 ( doubly y , double  x ) 

Parameters:

1. x - This is a real floating point value representing the x coordinate.
2. y - This is the actual numerical value of floating point representing y coordinate.

Return value:

This function returns arctan of y / x, in the [-pi, + pi] radian segment.

For example:

The following C program illustrates the usage of atan2 () function in C:

 #include #include #define  PI  3.14159265 int  main  () { double  x ,  y ,  ret ,  val ;  x  = - 7.0 ;  y  = 7.0 ;  val  = 180.0 /  PI ;  ret  =  atan2  ( y , x ) *  val ;  printf ( "Gia tri arctan2 cua x = %lf, y = %lf " ,  x ,  y );  printf ( "la bang %lfn" ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

5. Function cos () in C

The double cos function (double x) in Library C returns the cos of the angle x (measured in radians).

Declaring the function cos () in C

Below is the declaration for the function cos () in C:

 double  cos ( double  x ) 

Parameters:

x - This is a real floating point value representing an angle expressed in radian values.

Return value:

This function returns the cos of x.

For example:

The following program C illustrates the usage of function cos () in C:

 #include #include #define  PI  3.14159265 int  main  () { double  x ,  ret ,  val ;  x  = 60.0 ;  val  =  PI  / 180.0 ;  ret  =  cos (  x * val  );  printf ( "Gia tri cosin cua %lf la bang %lfn" ,  x ,  ret );  x  = 90.0 ;  val  =  PI  / 180.0 ;  ret  =  cos (  x * val  );  printf ( "Gia tri cosin cua %lf la bang %lfn" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

6. Cosh () function in C

The double cosh (double x) function in Library C returns the hyperbolic cosine of x.

Declare the function cosh () in C

Below is the declaration for the cosh () function in C:

 double  cosh ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns the hyperbolic cosine of x.

For example:

The following C program illustrates the usage of the cosh () function in C:

 #include #include int  main  () { double  x ;  x  = 0.5 ;  printf ( "Gia tri hyperbolic cosine cua %lf la bang %lfn" ,  x ,  cosh ( x ));  x  = 1.0 ;  printf ( "Gia tri hyperbolic cosine cua %lf la bang %lfn" ,  x ,  cosh ( x ));  x  = 1.5 ;  printf ( "Gia tri hyperbolic cosine cua %lf la bang %lfn" ,  x ,  cosh ( x )); return ( 0 ); } 

Compiling and running the above C program will result:

7. Function sin () in C

The double sin (double x) function in Library C returns the sine of the angle x (radian value).

Declaring the function sin () in C

Below is the declaration for function sin () in C:

 double  sin ( double  x ) 

Parameters:

x - This is a real floating point value representing an angle expressed in radian values.

Return value:

This function returns the sine of x.

For example:

The following C program illustrates the usage of the function sin () in C:

 #include #include #define  PI  3.14159265 int  main  () { double  x ,  ret ,  val ;  x  = 45.0 ;  val  =  PI  / 180 ;  ret  =  sin ( x * val );  printf ( "Sin cua %lf bang %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

8. The generating function () in C

The double function generates (double x) in Library C returns the hyperbolic sine of x.

Declare the generating function () in C

Below is the declaration for the generating function () in C:

 double  sinh ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns the hyperbolic sine of x.

For example:

The following program C illustrates the usage of the generating function () in C:

 #include #include int  main  () { double  x ,  ret ;  x  = 0.5 ;  ret  =  sinh ( x );  printf ( "Hyperbolic sine cua %lf bang %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

9. Ham function () in C

The function double tanh (double x) in Library C returns the hyperbolic tangent of x.

Declaring fish function () in C

Below is the declaration for the fishy function () in C:

 double  tanh ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns the hyperbolic tangent of x.

For example:

The following program C illustrates the usage of the fishy function () in C:

 #include #include int  main  () { double  x ,  ret ;  x  = 0.5 ;  ret  =  tanh ( x );  printf ( "Hyperbolic tangent cua %lf bang %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

10. Function exp () in C

The function double exp (double x) in Library C returns e hats x.

Declare the function exp () in C

Below is the declaration for exp () in C:

 double  exp ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns ex.

For example:

The following C program illustrates the usage of exp () in C:

 #include #include int  main  () { double  x  = 0 ;  printf ( "e^%lf = %lfn" ,  x ,  exp ( x ));  printf ( "e^%lf = %lfn" ,  x + 1 ,  exp ( x + 1 ));  printf ( "e^%lf = %lfn" ,  x + 2 ,  exp ( x + 2 )); return ( 0 ); } 

Compiling and running the above C program will result:

11. Function frexp () in C

The double frexp function (double x, int * exponent) in Library C returns the mantissa (the mantissa) and the integer pointed to by exponent (exponent). The result value is x = mantissa * 2 ^ exponent.

Declaring the function frexp () in C

Below is the declaration for frexp () function in C:

 double  frexp ( double  x , int * exponent ) 

Parameters:

x - This is the actual floating point number value to be calculated.

exponent - This is the pointer to an int object where the exponent value is stored.

Return value:

This function returns the mantissa and the integer pointed to by exponent.

For example:

The following program C illustrates the usage of frexp () function in C:

 #include #include int  main  () { double  x  = 1024 ,  fraction ; int  e ;  fraction  =  frexp ( x , & e );  printf ( "x = %.2lf = %.2lf * 2^%dn" ,  x ,  fraction ,  e ); return ( 0 ); } 

Compiling and running the above C program will result:

12. The ldexp () function in C

The double ldexp (double x, int exponent) function in Library C returns x * 2exponent.

Declare the function ldexp () in C

Below is the declaration for ldexp () in C:

 double  ldexp ( double  x , int  exponent ) 

Parameters:

x - This is the actual floating point number, also representing the number of digits after the comma.

exponent - This is the value of exponent.

Return value:

This function returns x * 2 exp

For example:

The following C program illustrates the usage of ldexp () in C:

 #include #include int  main  () { double  x ,  ret ; int  n ;  x  = 0.65 ;  n  = 3 ;  ret  =  ldexp ( x  , n );  printf ( "%f * 2^%d = %fn" ,  x ,  n ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

13. Log () function in C

The double log (double x) function in Library C returns lnx.

Declare the log () function in C

Below is the declaration for the log () function in C:

 double  log ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns lnx.

For example:

The following C program illustrates the usage of the log () function in C:

 #include #include int  main  () { double  x ,  ret ;  x  = 2.7 ; /* tim gia tri cua log(2.7) */  ret  =  log ( x );  printf ( "log(%lf) = %lf" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

14. Log10 () function in C

The double log10 function (double x) in Library C returns log10 (x).

Declare log10 () function in C

Below is the declaration for log10 () function in C:

 double  log10 ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns log10 (x), with x greater than 0.

For example:

The following C program illustrates how to use the log10 () function in C:

 #include #include int  main  () { double  x ,  ret ;  x  = 1000 ; /* tim gia tri cua log 10 1000 */  ret  =  log10 ( x );  printf ( "log10(%lf) = %lfn" ,  x ,  ret ); return ( 0 ); } 

Compiling and running the above C program will result:

15. Modf () function in C

The function double modf (double x, double * integer) in Library C returns the decimal part of x.

Declare the modf () function in C

Below is the declaration for the modf () function in C:

 double  modf ( double  x , double * integer ) 

Parameters:

x - This is the floating point real number value.

integer - This is a pointer to an object where the integer part is stored.

Return value:

This function returns the decimal part of x, with the same sign.

For example:

The following C program illustrates the usage of the modf () function in C:

 #include #include int  main  () { double  x ,  fractpart ,  intpart ;  x  = 7.123456 ;  fractpart  =  modf ( x , & intpart );  printf ( "Phan nguyen = %lfn" ,  intpart );  printf ( "Phan thap phan = %lf n" ,  fractpart ); return ( 0 ); } 

Compiling and running the above C program will result:

16. The pow () function in C

Double pow function (double x, double y) in Library C returns xy.

Declare the function pow () in C

Below is the declaration for pow () in C:

 double  pow ( double  x , double  y ) 

Parameters:

1. x - This is the radix, which is a floating point real number value.
2. y - This is an exponent, which is a floating point real number value.

Return value:

This function returns xy.

For example:

The following program C illustrates the usage of the pow () function in C:

 #include #include int  main  () {  printf ( "9.0 ^ 3 = %lfn" ,  pow ( 9.0 , 3 ));  printf ( "4.05 ^ 2.98 = %lf" ,  pow ( 4.05 , 2.98 )); return ( 0 ); } 

Compiling and running the above C program will result:

17. The sqrt () function in C

The function double sqrt (double x) in Library C returns the square root of x.

Declare the function sqrt () in C

Below is the declaration for the sqrt () function in C:

 double  sqrt ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns the square root of x.

For example:

The following C program illustrates the usage of the sqrt () function in C:

 #include #include int  main  () {  printf ( "Can bac hai cua %lf bang %lfn" , 4.0 ,  sqrt ( 4.0 ) );  printf ( "Can bac hai cua %lf bang %lfn" , 5.0 ,  sqrt ( 5.0 ) ); return ( 0 ); } 

Compiling and running the above C program will result:

18. Function ceil () in C

The double ceil (double x) function in Library C returns the smallest integer value greater than or equal to x.

Declare the function ceil () in C

Below is the declaration for the function ceil () in C:

 double  ceil ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

Returns the smallest integer value not less than x.

For example:

The following program C illustrates the usage of the function ceil () in C:

 #include #include int  main  () { float  val1 ,  val2 ,  val3 ,  val4 ;  val1  = 1.6 ;  val2  = 1.2 ;  val3  = 2.8 ;  val4  = 2.3 ;  printf  ( "Gia tri cua ceil(%.1f) = %.1lfn" ,  val1 ,  ceil ( val1 ));  printf  ( "Gia tri cua ceil(%.1f) = %.1lfn" ,  val2 ,  ceil ( val2 ));  printf  ( "Gia tri cua ceil(%.1f) = %.1lfn" ,  val3 ,  ceil ( val3 ));  printf  ( "Gia tri cua ceil(%.1f) = %.1lfn" ,  val4 ,  ceil ( val4 )); return ( 0 ); } 

Compiling and running the above C program will result:

19. The fabs () function in C

The function double fabs (double x) in Library C returns the absolute value of x.

Declare fabs () in C

Below is the declaration for fabs () in C:

 double  fabs ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns the absolute value of x.

For example:

The following C program illustrates the usage of the fabs () function in C:

 #include #include int  main  () { int  a ,  b ;  a  = 345 ;  b  = - 345 ;  printf ( "Tri tuyet doi: |%d| = %lfn" ,  a ,  fabs ( a ));  printf ( "Tri tuyet doi: |%d| = %lfn" ,  b ,  fabs ( b )); return ( 0 ); } 

Compiling and running the above C program will result:

20. Floor () function in C

The double floor (double x) function in Library C returns the largest integer value less than or equal to x.

Declare the floor () function in C

Below is the declaration for the floor () function in C:

 double  floor ( double  x ) 

Parameters:

x - This is the floating point real number value.

Return value:

This function returns the largest integer not greater than x.

For example:

The following program C illustrates the usage of the floor () function in C:

 #include #include int  main  () { float  val1 ,  val2 ,  val3 ,  val4 ;  val1  = 1.6 ;  val2  = 1.2 ;  val3  = 2.8 ;  val4  = 2.3 ;  printf ( "Gia tri cua floor(%.1f) = %.1lfn" ,  val1 ,  floor ( val1 ));  printf ( "Gia tri cua floor(%.1f) = %.1lfn" ,  val2 ,  floor ( val2 ));  printf ( "Gia tri cua floor(%.1f) = %.1lfn" ,  val3 ,  floor ( val3 ));  printf ( "Gia tri cua floor(%.1f) = %.1lfn" ,  val4 ,  floor ( val4 )); return ( 0 ); } 

Compiling and running the above C program will result:

21. Function fmod () in C

Double fmod (double x, double y) in Library C returns the remainder of the division x / y.

Declaring the function fmod () in C

Here is the declaration for fmod () function in C:

 double  fmod ( double  x , double  y ) 

Parameters:

x - This is a floating point numerical value that serves as a numerator.

y - This is a floating point numerical value that serves as a denominator.

Return value:

This function returns the remainder of the x / y division.

For example:

The following program C illustrates the usage of the fmod () function in C:

 #include #include int  main  () { float  a ,  b ; int  c ;  a  = 9.2 ;  b  = 3.7 ;  c  = 2 ;  printf ( "Phan du cua phep chia %f / %d la %lfn" ,  a ,  c ,  fmod ( a , c ));  printf ( "Phan du cua phep chia %f / %f la %lfn" ,  a ,  b ,  fmod ( a , b )); return ( 0 ); } 

Compiling and running the above C program will result:

  According to Tutorialspoint