Webmaster in a Nutshell, Third Edition

Name

Math

Synopsis

Math.constant
Math.function( )

Description

The Math object is a placeholder for grouping mathematical constants and functions. It does not define a class of objects as Date and String do. There is no Math( ) constructor, and functions like Math.sin( ) are simply functions, not methods that operate on an object.

Constants

Math.E

The constant e, the base of the natural logarithm.

Math.LN10

The natural logarithm of 10.

Math.LN2

The natural logarithm of 2.

Math.LOG10E

The base-10 logarithm of e.

Math.LOG2E

The base-2 logarithm of e.

Math.PI

The constant π.

Math.SQRT1_2

1 divided by the square root of 2.

Math.SQRT2

The square root of 2.

Functions

Math.abs( x )

Returns the absolute value of x.

Math.acos( x )

Returns the arc cosine of x; the return value is between 0 and π radians.

Math.asin( x )

Returns the arc sine of x; the return value is between -π/2 and π/2 radians.

Math.atan( x )

Returns the arc tangent of x; the return value is between -π/2 and π/2 radians.

Math.atan2( y, x )

Returns a value between -π and π radians that specifies the counterclockwise angle between the positive X-axis and the point (x, y). Note the order of the arguments to this function.

Math.ceil( x )

Returns the nearest integer greater than or equal to x.

Math.cos( x )

Returns the cosine of the specified value x.

Math.exp( x )

Returns the constant e raised to the power of x.

Math.floor( x )

Returns the nearest integer less than or equal to x.

Math.log( x )

Returns the natural logarithm ...