# Programming Ruby ### The Pragmatic Programmer's Guide
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module Math

### Index:

atan2 cos exp frexp ldexp log log10 sin sqrt tan

The `Math` module contains module functions for basic trigonometric and transcendental functions.

constants

`E` | 2.718281828 | Value of e (base of natural logarithms)

`PI` | 3.141592654 | Value of PI

class methods
atan2 | Math.atan2( y, x ) -> aFloat
|  | Computes the arc tangent given y and x. Returns -PI..PI.
cos | Math.cos( aNumeric ) -> aFloat
|  | Computes the cosine of aNumeric (expressed in radians). Returns -1..1.
exp | Math.exp( aNumeric ) -> aFloat
|  | Returns e raised to the power of aNumeric.
frexp | Math.frexp( aNumeric ) -> anArray
|  | Returns a two-element array ([aFloat, aFixnum]) containing the normalized fraction and exponent of aNumeric.
ldexp | Math.ldexp( aFloat, anInteger ) -> aFloat
|  | Returns the value of aFloat *2 anInteger .
log | Math.log( aNumeric ) -> aFloat
|  | Returns the natural logarithm of aNumeric.
log10 | Math.log10( aNumeric ) -> aFloat
|  | Returns the base 10 logarithm of aNumeric.
sin | Math.sin( aNumeric ) -> aFloat
|  | Computes the sine of aNumeric (expressed in radians). Returns -1..1.
sqrt | Math.sqrt( aNumeric ) -> aFloat
|  | Returns the non-negative square root of aNumeric. Raises `ArgError` if aNumeric is less than zero.
tan | Math.tan( aNumeric ) -> aFloat
|  | Returns the tangent of aNumeric (expressed in radians).

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Extracted from the book "Programming Ruby - The Pragmatic Programmer's Guide"
Copyright © 2001 by Addison Wesley Longman, Inc. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/)).

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