## Trigonometry Functions

These functions are used in geometric calculations to determine the size of angles. They all return radian values:

**sin( $num )**

Returns the sine of $num in radians.**cos( $num )**

Returns the cosine of $num in radians.**tan****( $num )**

Returns the tangent of $num in radians**asin****( $num )**

Returns the arc sine of $num in radians.**acos( $num )**Returns the arc cosine of $num in radians.**atan( $num )**Returns the arc tangent of $num in radians.**atan2( $y, $x)**Returns arc tangent of $x/$y where the sign of both parameters determines the quadrant of the result.

These functions convert values between radians and degrees.

**deg2rad( $num )**Converts the $num from degrees to radians and returns the result.**rad2deg( $num )**Converts the $num from radians to degrees and returns the result.

## Square Root, PI, and Power

**pi()**

Returns pie value 3.14159265359.**pow( $num, $exponent )**

$num raised to the power of $exponent. If both parameters are non-negative integers and the result can be represented as an integer, the result will be returned with int type, otherwise it will be returned as a float.**sqrt( $num )**Returns the square root of $num.

## Logarithm Functions

**exp( $num )**Returns`e`

raised to the number power.**e**is the base of the natural system of logarithms, or approximately 2.718282. For example, the`echo exp(5.7);`

returns 298.87.**log( $num, $base = M_E)**Returns the natural logarithm of $num. If the optional base parameter is specified, it returns log_{$base}$num.**log10( $num )**Base-10 logarithm of $num.

**Doing Math:**