Web Standards Programmer's Reference: HTML, CSS, JavaScript®, Perl, Python®, and PHP

F.20. Math

Function	Returns	Description
abs(int number)	int	Returns the absolute value of the number.
ceil(float number)	float	Returns the next highest integer value of the number.
floor(float number)	float	Returns the next lowest integer value from the number.
round(float number [, int precision])	float	Returns the number rounded to specified precision.
sin(float number)	float	Returns the sine of the number in radians.
cos(float number)	float	Returns the cosine of the number in radians.
tan(float number)	float	Returns the tangent of the number in radians.
asin(float number)	float	Returns the arc sine of the number in radians.
acos(float number)	float	Returns the arc cosine of the number in radians.
atan(float number)	float	Returns the arc tangent of the number in radians.
atan2(float y, float x)	float	Returns the arc tangent of y/x, with the resulting quadrant determined by the signs of y and x.
sinh(float number)	float	Returns the hyperbolic sine of the number, defined as (exp(number) - exp(-number))/2.
cosh(float number)	float	Returns the hyperbolic cosine of the number, defined as (exp(number) + exp(-number))/2.
tanh(float number)	float	Returns the hyperbolic tangent of the number, defined as sinh(number)/cosh(number).
asinh(float number)	float	Returns the inverse hyperbolic sine of the number, that is, the value whose hyperbolic sine is number.
acosh(float number)	float	Returns the inverse hyperbolic cosine of the number, that is, the value whose hyperbolic cosine is number.
atanh(float number) ...