$atan2

Calculates the arctangent (in radians) of the quotient of two numbers.

$atan2(number1,number2)

number1	a number, or an expression that evaluates to a number
number2	a number, or an expression that evaluates to a number

Number, with the same number of decimal places as number1.

Number1 is divided by number2 before the arctangent is calculated.

The value returned by $atan2 has the same number of decimal places as number1.

$atan2(1.000,2)

The above command is equivalent to $atan(0.500) and returns the value 0.464.