The mathematical library function declaration in the MATH.H, mainly includes:
1. ABS (x) to calculate the absolute value of integer number x
2, cos (x) x (radian) cosine
3, Fabs (x) to find the absolute value of the floating-point number X
4, Ceil (x) to find the smallest integer less than x
5, floor (x) to find the smallest integer greater than X
6, log (x) to find the natural logarithm of X
7, LOG10 (x) to find the logarithm of x (bottom 10)
8, pow (x, y) to find X's Y-second side
Function Description:
POW () is used to calculate Y-square values with x as the base, that is, XY values, and then return the results.
return value:
Returns the Y-second-side calculation of X.
9, sin (x) for the sine of X (radians)
Function Description:
Sin () is used to calculate the positive value of the parameter x, and then returns the result.
return value:
Returns the calculated results from 1 through 1.
10, sqrt (x) to find the square root of X
11, ACOs (x) to seek the reverse cosine
Function Description:
ACOs () is used to calculate the inverse cosine of the parameter x, and then returns the result. The parameter x range is between 1 and 1 and will fail if it exceeds this range.
return value:
Returns the calculated result between 0 and pi, in radians, in radians in the function library.
12, ASIN (s) to the anyway string
Function Description:
ASIN () is used to calculate the inverse chord value of the parameter x, and then returns the result. The parameter x range is between 1 and 1 and will fail if it exceeds this range.
return value:
Returns the result of the calculation between the PI/2 of the-PI/2.
13, Atan (x)
Function Description:
Atan () is used to calculate the tangent value of the parameter x, and then returns the result.
return value:
Returns the result of the calculation between-PI/2 and PI/2.
14, atan2 (x)
Function Description:
ATAN2 () is used to calculate the tangent value of the parameter y/x, and then returns the result.
return value:
Returns the result of the calculation between-PI/2 and PI/2.
15, exp (calculation index)
Function Description:
EXP () is used to calculate the X-square value, the ex value, at the base of E, and then return the result.
return value:
Returns the X-square calculation result of E.
16, Frexp (the number of floating-point types into the base and index)
Function Description:
Frexp () is used to cut the floating-point number of parameter x to base and exponent. The base part is returned directly, the exponent part is returned by the parameter exp pointer, and the return value is multiplied by the value of 2 for the exp secondary square.
return value:
Returns the base portion of the parameter x, and the exponent part is at the address indicated by the EXP pointer.
Copy Code code as follows:
Main ()
{
int exp;
Double fraction,i;
fraction = Frexp (1024,&EXP);
I=ldexp (FRACTION,EXP);
printf ("exp =%d\n", exp);
printf ("fraction =%f\n", fraction);
printf ("i=%f", I);
}
17, Ldexp (Calculate 2 of the second square value)
Function Description:
Ldexp () is used to multiply the parameter x by 2 of the exp quadratic value, that is, the x*2exp.
return value:
Returns the result of the calculation.
/* Compute 3* (2^2) =12 * *
Copy Code code as follows:
Main ()
{
int exp;
Double x,answer;
Answer = LDEXP (3,2);
printf ("3*2^ (2) =%f\n", answer);
}
18, log (to calculate the value of an e-base)
Function Description:
Log () is used to calculate an X pair value with an E, and then returns the result.
return value:
Returns the natural pair value of the parameter x.
Copy Code code as follows:
Main ()
{
Double answer;
Answer = log (100);
printf ("log (m) =%f\n", answer);
}
19, log10 (calculated with a value of 10)
20, Sinh (take the double curve positive and black function value)
Function Description:
Sinh () is used to calculate the hyperbolic positive values of the parameter x, and then returns the result. The mathematical definition is: (exp (x)-exp (-X))/2.
return value:
Returns the hyperbolic positive value of the parameter x.
Copy Code code as follows:
Main ()
{
Double answer = sinh (0.5);
printf ("sinh (0.5) =%f\n", answer);
}