The math.h header file includes declarations of mathematical functions.
All the functions return a value of type double.
Functions for Numerical Calculations
|floor(x)|| Returns the largest integer that isn't greater than x as type double|
|ceil(x)|| Returns the smallest integer that isn't less than x as type double|
|fabs(x)|| Returns the absolute value of x|
|log(x)|| Returns the natural logarithm (base e) of x|
|log10(x)|| Returns the logarithm to base 10 of x|
|exp(x)|| Returns the value of ex|
| Returns the square root of x|
Returns the value xy
There are versions of these for types float and long double that have f or l, respectively, appended to the function name.
ceilf() applies to float values and sqrtl() applies to long double values, for example.
Here are some examples demonstrating use of the functions:
double x = 2.25; double less = 0.0; double more = 0.0; double root = 0.0; less = floor(x); // Result is 2.0 more = ceil(x); // Result is 3.0 root = sqrt(x); // Result is 1.5
The following table lists trigonometric functions.
Those for types, float and type long double have f or l, respectively, appended to the name.
Arguments and values returned are of type float, type double, or type long double and angles are expressed in radians.
|sin(x)||Sine of x expressed in radians|
|cos(x)||Cosine of x|
|tan(x)||Tangent of x|
Here are some examples:
double angle = 45.0; // Angle in degrees double pi = 3.14159265; double sine = 0.0; double cosine = 0.0; sine = sin(pi*angle/180.0); // Angle converted to radians cosine = sin(pi*angle/180.0); // Angle converted to radians
Dividing an angle measured in degrees by 180 and multiplying by the value of p will produce the angle in radians, as required by these functions.
The inverse trigonometric functions are available: asin(), acos(), and atan()
The hyperbolic functions are sinh(), cosh(), and tanh().