# ActionScript 2.0 Language Reference for Macromedia Flash 8 - page 49

### Math

```Object

+-Math

public class

Math

extends Object
```

The Math class is a top-level class whose methods and properties you can use without using a constructor.

Use the methods and properties of this class to access and manipulate mathematical constants and functions. All the properties and methods of the Math class are static and must be called using the syntax Math.method ( parameter ) or Math.constant . In ActionScript, constants are defined with the maximum precision of double-precision IEEE-754 floating-point numbers .

Several Math class methods use the measure of an angle in radians as a parameter.You can use the following equation to calculate radian values before calling the method and then provide the calculated value as the parameter, or you can provide the entire right side of the equation (with the angle's measure in degrees in place of degrees ) as the radian parameter.

To calculate a radian value, use the following formula:

```radians = degrees * Math.PI/180
```

The following is an example of passing the equation as a parameter to calculate the sine of a 45° angle:

```Math.sin(45 * Math.PI/180) is the same as Math.sin(.7854)
```

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Property summary

Modifiers

Property

Description

static

E:Number

A mathematical constant for the base of natural logarithms, expressed as e .

static

LN10:Number

A mathematical constant for the natural logarithm of 10, expressed as loge10, with an approximate value of 2.302585092994046.

static

LN2:Number

A mathematical constant for the natural logarithm of 2, expressed as loge2, with an approximate value of 0.6931471805599453.

static

LOG10E:Number

A mathematical constant for the base-10 logarithm of the constant e ( Math.E ), expressed as log10e, with an approximate value of 0.4342944819032518.

static

LOG2E:Number

A mathematical constant for the base-2 logarithm of the constant e ( Math.E ), expressed as log2e, with an approximate value of 1.442695040888963387.

static

PI:Number

A mathematical constant for the ratio of the circumference of a circle to its diameter, expressed as pi, with a value of 3.141592653589793.

static

SQRT1_2:Number

A mathematical constant for the square root of one-half, with an approximate value of 0.7071067811865476.

static

SQRT2:Number

A mathematical constant for the square root of 2, with an approximate value of 1.4142135623730951.

Properties inherited from class Object

 ```constructor (Object.constructor property), __proto__ (Object.__proto__ property), prototype (Object.prototype property), __resolve (Object.__resolve property) ```

Method summary

Modifiers

Signature

Description

static

abs(x:Number) : Number

Computes and returns an absolute value for the number specified by the parameter x .

static

acos(x:Number) : Number

Computes and returns the arc cosine of the number specified in the parameter x , in radians.

static

asin(x:Number) : Number

Computes and returns the arc sine for the number specified in the parameter x , in radians.

static

atan(tangent:Number) : Number

Computes and returns the value, in radians, of the angle whose tangent is specified in the parameter tangent .

static

atan2(y:Number, x:Number) : Number

Computes and returns the angle of the point y / x in radians, when measured counterclockwise from a circle's x axis (where 0,0 represents the center of the circle).

static

ceil(x:Number) : Number

Returns the ceiling of the specified number or expression.

static

cos(x:Number) : Number

Computes and returns the cosine of the specified angle in radians.

static

exp(x:Number) : Number

Returns the value of the base of the natural logarithm ( e ), to the power of the exponent specified in the parameter x .

static

floor(x:Number) : Number

Returns the floor of the number or expression specified in the parameter x .

static

log(x:Number) : Number

Returns the natural logarithm of parameter x .

static

max(x:Number, y:Number) : Number

Evaluates x and y and returns the larger value.

static

min(x:Number, y:Number) : Number

Evaluates x and y and returns the smaller value.

static

pow(x:Number, y:Number) : Number

Computes and returns x to the power of y .

static

random() : Number

Returns a pseudo-random number n, where 0 <= n < 1.

static

round(x:Number) : Number

Rounds the value of the parameter x up or down to the nearest integer and returns the value.

static

sin(x:Number) : Number

Computes and returns the sine of the specified angle in radians.

static

sqrt(x:Number) : Number

Computes and returns the square root of the specified number.

static

tan(x:Number) : Number

Computes and returns the tangent of the specified angle.

Methods inherited from class Object

 ```addProperty (Object.addProperty method), hasOwnProperty (Object.hasOwnProperty method), isPropertyEnumerable (Object.isPropertyEnumerable method), isPrototypeOf (Object.isPrototypeOf method), registerClass (Object.registerClass method), toString (Object.toString method), unwatch (Object.unwatch method), valueOf (Object.valueOf method), watch (Object.watch method) ```

#### abs (Math.abs method)

```public static abs(x:Number) : Number
```

Computes and returns an absolute value for the number specified by the parameter x .

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number.

Returns

Number - A number.

Example

The following example shows how Math.abs() returns the absolute value of a number and does not affect the value of the x parameter (called num in this example):

```var num:Number = -12;

var numAbsolute:Number = Math.abs(num);

trace(num); // output: -12

trace(numAbsolute); // output: 12
```

#### acos (Math.acos method)

```public static acos(x:Number) : Number
```

Computes and returns the arc cosine of the number specified in the parameter x , in radians.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number from -1.0 to 1.0.

Returns

Number - A number; the arc cosine of the parameter x .

Example

The following example displays the arc cosine for several values.

```trace(Math.acos(-1)); // output: 3.14159265358979

trace(Math.acos(0)); // output: 1.5707963267949

trace(Math.acos(1)); // output: 0
```

```asin (Math.asin method), atan (Math.atan method), atan2 (Math.atan2 method),

cos (Math.cos method), sin (Math.sin method), tan (Math.tan method)
```

#### asin (Math.asin method)

```public static asin(x:Number) : Number
```

Computes and returns the arc sine for the number specified in the parameter x , in radians.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number from -1.0 to 1.0.

Returns

Number - A number between negative pi divided by 2 and positive pi divided by 2.

Example

The following example displays the arc sine for several values.

```trace(Math.asin(-1)); // output: -1.5707963267949

trace(Math.asin(0)); // output: 0

trace(Math.asin(1)); // output: 1.5707963267949
```

```acos (Math.acos method), atan (Math.atan method), atan2 (Math.atan2 method),

cos (Math.cos method), sin (Math.sin method), tan (Math.tan method)
```

#### atan (Math.atan method)

```public static atan(tangent:Number) : Number
```

Computes and returns the value, in radians, of the angle whose tangent is specified in the parameter tangent . The return value is between negative pi divided by 2 and positive pi divided by 2.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

tangent :Number - A number that represents the tangent of an angle.

Returns

Number - A number between negative pi divided by 2 and positive pi divided by 2.

Example

The following example displays the angle value for several tangents.

```trace(Math.atan(-1)); // output: -0.785398163397448

trace(Math.atan(0)); // output: 0

trace(Math.atan(1)); // output: 0.785398163397448
```

```acos (Math.acos method), asin (Math.asin method), atan2 (Math.atan2 method),

cos (Math.cos method), sin (Math.sin method), tan (Math.tan method)
```

#### atan2 (Math.atan2 method)

```public static atan2(y:Number, x:Number) : Number
```

Computes and returns the angle of the point y / x in radians, when measured counterclockwise from a circle's x axis (where 0,0 represents the center of the circle). The return value is between positive pi and negative pi.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

y :Number - A number specifying the y coordinate of the point.

x :Number - A number specifying the x coordinate of the point.

Returns

Number - A number.

Example

The following example returns the angle, in radians, of the point specified by the coordinates (0, 10), such that x = 0 and y = 10. Note that the first parameter to atan2 is always the y coordinate.

TRace(Math.atan2(10, 0)); // output: 1.5707963267949

```acos (Math.acos method), asin (Math.asin method), atan (Math.atan method), cos

(Math.cos method), sin (Math.sin method), tan (Math.tan method)
```

#### ceil (Math.ceil method)

```public static ceil(x:Number) : Number
```

Returns the ceiling of the specified number or expression. The ceiling of a number is the closest integer that is greater than or equal to the number.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number or expression.

Returns

Number - An integer that is both closest to, and greater than or equal to, parameter x .

Example

The following code returns a value of 13:

Math.ceil(12.5);

```floor (Math.floor method), round (Math.round method)
```

#### cos (Math.cos method)

```public static cos(x:Number) : Number
```

Computes and returns the cosine of the specified angle in radians. To calculate a radian, see the description of the Math class entry.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number that represents an angle measured in radians.

Returns

Number - A number from -1.0 to 1.0.

Example

The following example displays the cosine for several different angles.

```trace (Math.cos(0)); // 0 degree angle. Output: 1

trace (Math.cos(Math.PI/2)); // 90 degree angle. Output: 6.12303176911189e-

17

trace (Math.cos(Math.PI)); // 180 degree angle. Output: -1

trace (Math.cos(Math.PI*2)); // 360 degree angle. Output: 1
```

Note: The cosine of a 90 degree angle is zero, but because of the inherent inaccuracy of decimal calculations using binary numbers, Flash Player will report a number extremely close to, but not exactly equal to, zero.

```acos (Math.acos method), asin (Math.asin method), atan (Math.atan method),

atan2 (Math.atan2 method), sin (Math.sin method), tan (Math.tan method)
```

#### E (Math.E property)

```public static E : Number
```

A mathematical constant for the base of natural logarithms, expressed as e . The approximate value of e is 2.71828182845905.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

This example shows how Math.E is used to compute continuously compounded interest for a simple case of 100 percent interest over a one-year period.

```var principal:Number = 100;

var simpleInterest:Number = 100;

var continuouslyCompoundedInterest:Number = (100 * Math.E) - principal;

trace ("Beginning principal: \$" + principal);

trace ("Simple interest after one year: \$" + simpleInterest);

trace ("Continuously compounded interest after one year: \$" +

continuouslyCompoundedInterest);

//

Output:

Beginning principal: 0

Simple interest after one year: 0

Continuously compounded interest after one year: 1.828182845905
```

#### exp (Math.exp method)

```public static exp(x:Number) : Number
```

Returns the value of the base of the natural logarithm ( e ), to the power of the exponent specified in the parameter x . The constant Math.E can provide the value of e .

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - The exponent; a number or expression.

Returns

Number - A number.

Example

The following example displays the logarithm for two number values.

```trace(Math.exp(1)); // output: 2.71828182845905

trace(Math.exp(2)); // output: 7.38905609893065
```

```E (Math.E property)
```

#### floor (Math.floor method)

```public static floor(x:Number) : Number
```

Returns the floor of the number or expression specified in the parameter x . The floor is the closest integer that is less than or equal to the specified number or expression.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number or expression.

Returns

Number - The integer that is both closest to, and less than or equal to, parameter x .

Example

The following code returns a value of 12:

Math.floor(12.5);

The following code returns a value of -7:

Math.floor(-6.5);

#### LN10 (Math.LN10 property)

```public static LN10 : Number
```

A mathematical constant for the natural logarithm of 10, expressed as loge10, with an approximate value of 2.302585092994046.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

This example traces the value of Math.LN10 .

```trace(Math.LN10);

// output: 2.30258509299405
```

#### LN2 (Math.LN2 property)

```public static LN2 : Number
```

A mathematical constant for the natural logarithm of 2, expressed as loge2, with an approximate value of 0.6931471805599453.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

#### log (Math.log method)

```public static log(x:Number) : Number
```

Returns the natural logarithm of parameter x .

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number or expression with a value greater than 0.

Returns

Number - The natural logarithm of parameter x .

Example

The following example displays the logarithm for three numerical values.

```trace(Math.log(0)); // output: -Infinity

trace(Math.log(1)); // output: 0

trace(Math.log(2)); // output: 0.693147180559945

trace(Math.log(Math.E)); // output: 1
```

#### LOG10E (Math.LOG10E property)

```public static LOG10E : Number
```

A mathematical constant for the base-10 logarithm of the constant e ( Math.E ), expressed as log10e, with an approximate value of 0.4342944819032518.

The Math.log() method computes the natural logarithm of a number. Multiply the result of Math.log() by Math.LOG10E obtain the base-10 logarithm.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

This example shows how to obtain the base-10 logarithm of a number:

```trace(Math.log(1000) * Math.LOG10E);

// Output: 3
```

#### LOG2E (Math.LOG2E property)

```public static LOG2E : Number
```

A mathematical constant for the base-2 logarithm of the constant e ( Math.E ), expressed as log2e, with an approximate value of 1.442695040888963387.

The Math.log method computes the natural logarithm of a number. Multiply the result of Math.log() by Math.LOG2E obtain the base-2 logarithm.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

This example shows how to obtain the base-2 logarithm of a number:

```trace(Math.log(16) * Math.LOG2E);

// Output: 4
```

#### max (Math.max method)

```public static max(x:Number, y:Number) : Number
```

Evaluates x and y and returns the larger value.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number or expression.

y :Number - A number or expression.

Returns

Number - A number.

Example

The following example displays Thu Dec 30 00:00:00 GMT-0700 2004 , which is the larger of the evaluated expressions.

```var date1:Date = new Date(2004, 11, 25);

var date2:Date = new Date(2004, 11, 30);

var maxDate:Number = Math.max(date1.getTime(), date2.getTime());

trace(new Date(maxDate).toString());
```

```min (Math.min method), Date
```

#### min (Math.min method)

```public static min(x:Number, y:Number) : Number
```

Evaluates x and y and returns the smaller value.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number or expression.

y :Number - A number or expression.

Returns

Number - A number.

Example

The following example displays Sat Dec 25 00:00:00 GMT-0700 2004 , which is the smaller of the evaluated expressions.

```var date1:Date = new Date(2004, 11, 25);

var date2:Date = new Date(2004, 11, 30);

var minDate:Number = Math.min(date1.getTime(), date2.getTime());

trace(new Date(minDate).toString());
```

```max (Math.max method)
```

#### PI (Math.PI property)

```public static PI : Number
```

A mathematical constant for the ratio of the circumference of a circle to its diameter, expressed as pi, with a value of 3.141592653589793.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

The following example draws a circle using the mathematical constant pi and the Drawing API.

```drawCircle(this, 100, 100, 50);

//

function drawCircle(mc:MovieClip, x:Number, y:Number, r:Number):Void {

mc.lineStyle(2, 0xFF0000, 100);

mc.moveTo(x+r, y);

mc.curveTo(r+x, Math.tan(Math.PI/8)*r+y, Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, r+y, x, r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, r+y, -Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-r+x, Math.tan(Math.PI/8)*r+y, -r+x, y);

mc.curveTo(-r+x, -Math.tan(Math.PI/8)*r+y, -Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, -r+y, x, -r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, -r+y, Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(r+x, -Math.tan(Math.PI/8)*r+y, r+x, y);

}
```

#### pow (Math.pow method)

```public static pow(x:Number, y:Number) : Number
```

Computes and returns x to the power of y .

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number to be raised to a power.

y :Number - A number specifying a power the parameter x is raised to.

Returns

Number - A number.

Example

The following example uses Math.pow and Math.sqrt to calculate the length of a line.

```this.createEmptyMovieClip("canvas_mc", this.getNextHighestDepth());

var mouseListener:Object = new Object();

mouseListener.onMouseDown = function() {

this.origX = _xmouse;

this.origY = _ymouse;

};

mouseListener.onMouseUp = function() {

this.newX = _xmouse;

this.newY = _ymouse;

var minY = Math.min(this.origY, this.newY);

var nextDepth:Number = canvas_mc.getNextHighestDepth();

var line_mc:MovieClip =

canvas_mc.createEmptyMovieClip("line"+nextDepth+"_mc", nextDepth);

line_mc.moveTo(this.origX, this.origY);

line_mc.lineStyle(2, 0x000000, 100);

line_mc.lineTo(this.newX, this.newY);

var hypLen:Number = Math.sqrt(Math.pow(line_mc._width,

2)+Math.pow(line_mc._height, 2));

line_mc.createTextField("length"+nextDepth+"_txt",

canvas_mc.getNextHighestDepth(), this.origX, this.origY-22, 100, 22);

line_mc['length'+nextDepth+'_txt'].text = Math.round(hypLen) +" pixels";

};

```

The MovieClip.getNextHighestDepth() method used in this example requires Flash Player 7 or later. If your SWF file includes a version 2 component, use the version 2 components DepthManager class instead of the MovieClip.getNextHighestDepth() method.

#### random (Math.random method)

```public static random() : Number
```

Returns a pseudo-random number n, where 0 <= n < 1. The number returned is a pseudo-random number because it is not generated by a truly random natural phenomenon such as radioactive decay.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Returns

Number - A number.

Example

The following example outputs 100 random integers between 4 and 11 (inclusively):

```function randRange(min:Number, max:Number):Number {

var randomNum:Number = Math.floor(Math.random() * (max - min + 1)) + min;

return randomNum;

}

for (var i = 0; i < 100; i++) {

var n:Number = randRange(4, 11)

trace(n);

}
```

#### round (Math.round method)

```public static round(x:Number) : Number
```

Rounds the value of the parameter x up or down to the nearest integer and returns the value. If parameter x is equidistant from its two nearest integers (that is, the number ends in .5), the value is rounded up to the next higher integer.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number.

Returns

Number - A number; an integer.

Example

The following example returns a random number between two specified integers.

```function randRange(min:Number, max:Number):Number {

var randomNum:Number = Math.round(Math.random() * (max-min+1) + (min-

.5));

return randomNum;

}

for (var i = 0; i<25; i++) {

trace(randRange(4, 11));

}
```

```ceil (Math.ceil method), floor (Math.floor method)
```

#### sin (Math.sin method)

```public static sin(x:Number) : Number
```

Computes and returns the sine of the specified angle in radians. To calculate a radian, see the description of the Math class entry.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number that represents an angle measured in radians.

Returns

Number - A number; the sine of the specified angle (between -1.0 and 1.0).

Example

The following example draws a circle using the mathematical constant pi, the sine of an angle, and the Drawing API.

```drawCircle(this, 100, 100, 50);

//

function drawCircle(mc:MovieClip, x:Number, y:Number, r:Number):Void {

mc.lineStyle(2, 0xFF0000, 100);

mc.moveTo(x+r, y);

mc.curveTo(r+x, Math.tan(Math.PI/8)*r+y, Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, r+y, x, r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, r+y, -Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-r+x, Math.tan(Math.PI/8)*r+y, -r+x, y);

mc.curveTo(-r+x, -Math.tan(Math.PI/8)*r+y, -Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, -r+y, x, -r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, -r+y, Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(r+x, -Math.tan(Math.PI/8)*r+y, r+x, y);

}
```

```acos (Math.acos method), asin (Math.asin method), atan (Math.atan method),

atan2 (Math.atan2 method), cos (Math.cos method), tan (Math.tan method)
```

#### sqrt (Math.sqrt method)

```public static sqrt(x:Number) : Number
```

Computes and returns the square root of the specified number.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number or expression greater than or equal to 0.

Returns

Number - A number if parameter x is greater than or equal to zero; NaN (not a number) otherwise .

Example

The following example uses Math.pow and Math.sqrt to calculate the length of a line.

```this.createEmptyMovieClip("canvas_mc", this.getNextHighestDepth());

var mouseListener:Object = new Object();

mouseListener.onMouseDown = function() {

this.origX = _xmouse;

this.origY = _ymouse;

};

mouseListener.onMouseUp = function() {

this.newX = _xmouse;

this.newY = _ymouse;

var minY = Math.min(this.origY, this.newY);

var nextDepth:Number = canvas_mc.getNextHighestDepth();

var line_mc:MovieClip =

canvas_mc.createEmptyMovieClip("line"+nextDepth+"_mc", nextDepth);

line_mc.moveTo(this.origX, this.origY);

line_mc.lineStyle(2, 0x000000, 100);

line_mc.lineTo(this.newX, this.newY);

var hypLen:Number = Math.sqrt(Math.pow(line_mc._width,

2)+Math.pow(line_mc._height, 2));

line_mc.createTextField("length"+nextDepth+"_txt",

canvas_mc.getNextHighestDepth(), this.origX, this.origY-22, 100, 22);

line_mc['length'+nextDepth+'_txt'].text = Math.round(hypLen) +" pixels";

};

```

#### SQRT1_2 (Math.SQRT1_2 property)

```public static SQRT1_2 : Number
```

A mathematical constant for the square root of one-half, with an approximate value of 0.7071067811865476.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

This example traces the value of Math.SQRT1_2 .

```trace(Math.SQRT1_2);

// Output: 0.707106781186548
```

#### SQRT2 (Math.SQRT2 property)

```public static SQRT2 : Number
```

A mathematical constant for the square root of 2, with an approximate value of 1.4142135623730951.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

This example traces the value of Math.SQRT2 .

```trace(Math.SQRT2);

// Output: 1.4142135623731
```

#### tan (Math.tan method)

```public static tan(x:Number) : Number
```

Computes and returns the tangent of the specified angle. To calculate a radian, use the information outlined in the introduction to the Math class.

Availability: ActionScript 1.0; Flash Player 5 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Parameters

x :Number - A number that represents an angle measured in radians.

Returns

Number - A number; tangent of parameter x .

Example

The following example draws a circle using the mathematical constant pi, the tangent of an angle, and the Drawing API.

```drawCircle(this, 100, 100, 50);

//

function drawCircle(mc:MovieClip, x:Number, y:Number, r:Number):Void {

mc.lineStyle(2, 0xFF0000, 100);

mc.moveTo(x+r, y);

mc.curveTo(r+x, Math.tan(Math.PI/8)*r+y, Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, r+y, x, r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, r+y, -Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-r+x, Math.tan(Math.PI/8)*r+y, -r+x, y);

mc.curveTo(-r+x, -Math.tan(Math.PI/8)*r+y, -Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, -r+y, x, -r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, -r+y, Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(r+x, -Math.tan(Math.PI/8)*r+y, r+x, y);

}
```

```acos (Math.acos method), asin (Math.asin method), atan (Math.atan method),