Math in ECMAScript 262
A global, noninstantiable object which holds certain mathrelated functions and values.
Inherits from:
Self Methods
name  returns  description 

abs(x)  Number 
Return the absolute value of x .

acos(x)  Number 
Return the arc cosine of x , in radians.

atan(x)  Number 
Return the arc tangent of x , in radians.

atan2(y,x)  Number 
Return the arc tangent of the quotient y /x , where the signs of y and x are used to determine the quadrant of the result, in radians.

ceil(x)  Number 
Return smallest integer which is larger than x (aka "round up").

cos(x)  Number 
Return the cosine of x , in radians.

exp(x)  Number  Return the value of e^{x}. 
floor(x)  Number 
Return largest integer which is less than x (aka "round down").

log(x)  Number 
Return the natural logarithm of x .

max([value1],[value2],[...])  Number  Return the largest of all arguments supplied. 
min([value1],[value2],[...])  Number  Return the smallest of all arguments supplied. 
pow(x,y)  Number 
Return the value of raising x to the power y .

random()  Number  Return a floatingpoint random number between 0 (inclusive) and 1 (exclusive). 
round(x)  Number  Round a number to the closest integer. 
sin(x)  Number 
Return the sine of x , in radians.

sqrt(x)  Number 
Return the square root of x .

tan(x)  Number 
Return the tangent of x , in radians.

Instance Properties
name  type  description 

constructor  Object  A reference to the constructor class for the current object instance. [from Object] 
prototype  Object  The prototype for a class. [from Object] 
Instance Methods
name  returns  description 

hasOwnProperty(propertyOrMethodName)  Boolean  Determines if the object/instance itself has the named property or method. [from Object] 
isPrototypeOf(instanceToTest)  Boolean  Determines if the calling object prototype is in the inheritance chain for the supplied argument. [from Object] 
propertyIsEnumerable(propertyOrMethodName)  Boolean 
Determines if the object/instance itself has a property or method of the supplied name which will appear in a for (prop in obj) enumeration.
[from Object]

toLocaleString()  String 
For most objects, the same as toString() unless explicitly overridden.
[from Object]

toString()  String  Returns a string representation of the object. [from Object] 
valueOf()  String 
Returns the internal this value of the object.
[from Object]

Constants
name  object  value  description 

E  Math  e  Roughly 2.7182818284590452354. 
LN10  Math  ln(10)  The natural logarithm of 10, roughly 2.302585092994046 
LN2  Math  ln(2)  The natural logarithm of 2, roughly 0.6931471805599453 
PI  Math  π  Roughly 3.1415926535897932 
SQRT1_2  Math  √(0.5)  The square root of 1/2, roughly 0.7071067811865476 
SQRT2  Math  √2  The square root of 2, roughly 1.4142135623730951 
LOG2E  Math  log_{2}(e)  The base2 logarithm of e, roughly 1/Math.LN2 or 1.4426950408889634 
LOG10E  Math  log_{10}(e)  The base10 logarithm of e, roughly 1/Math.LN10 or 0.4342944819032518 
Description
The
Math
object is global and noninstantiable. (It is an error to do something like var x = new Math()
.)
Invoke its methods directly as properties of the Class object itself, e.g.:var x = 12.784;
x = Math.round(x);
...instead of the following common mistakes which are invalid:
var x = 12.784;
x.round(); // *** INVALID CODE
round(x); // *** INVALID CODE