Javascript Math object

The Math object holds a set of constants and methods enabling more complex mathematical operations than the basic arithmetic operators

var root = Math.sqrt(10);

Constants Provided by the Math Object

Property	Description
Math.E	The base of the natural logarithm (Euler's constant e)
Math.LN2	Natural log of 2
Math.LN10	Natural log of 10
Math.LOG2E	Log (base 2) of e
Math.LOG10E	Log (base 10) of e
Math.PI	Pi (p)
Math.SQRT1_2	Square root of 0.5 (equivalently, one over the square root of 2)
Math.SQRT2	Square root of 2

Table 7-4: Methods Provided by the Math Object

Method	Returns
Math.abs(arg)	Absolute value of arg
Math.acos(arg)	Arc cosine of arg
Math.asin(arg)	Arc sine of arg
Math.atan(arg)	Arc tangent of arg
Math.atan2(y, x)	Angle between the x axis and the point (x, y), measured counterclockwise (like polar coordinates). Note how y is passed as the first argument rather than the second.
Math.ceil(arg)	Ceiling of arg (smallest integer greater than or equal to arg)
Math.cos(arg)	Cosine of arg
Math.exp(arg)	e to arg power
Math.floor(arg)	Floor of arg (greatest integer less than or equal to arg)
Math.log(arg)	Natural log of arg (log base e of arg)
Math.max(arg1, arg2)	The greater of arg1 or arg2
Math.min(arg1, arg2)	The lesser of arg1 or arg2
Math.pow(arg1, arg2)	arg1 to the arg2 power
Math.random()	A random number in the interval [0,1]
Math.round(arg)	The result of rounding arg to the nearest integer. If the decimal portion of arg is greater than or equal to .5, it is rounded up. Otherwise, arg is rounded down.
Math.sin(arg)	Sine of arg
Math.sqrt(arg)	Square root of arg
Math.tan(arg)	Tangent of arg

There are several aspects of the Math object that need to be kept in mind. The trigonometric methods work in radians, so you need to multiply any degree measurements by p / 180 before using them. Also, because of the imprecise characteristic of floating-point operations, you might notice minor deviations from the results you expect. For example, though the sine of p is 0, the following code:

alert(Math.sin(Math.PI));