+---------------------------------+
|              ATAN               |
+---------------------------------+
ATAN(<expN>)

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Returns (in radians) arc tangent of <expN>.
Return value - Numeric
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This trigonometric function returns the arc tangent of <expN>, an angle
in radians between -pi/2 and +pi/2.  The <expN> may be any value.

The numeric value returned by ATAN() is in radians; you may convert this
value to degrees with the RTOD() function.  The number of decimal places
returned by ATAN() is determined by the SET DECIMALS command.

+---------------------------------+
|           Examples              |
+---------------------------------+

? ATAN(0)

STORE PI()/2 to angle
? ATAN(angle)

? ATAN(PI()/2)

? ATAN(DTOR(90))

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See Also:  ATN2(), RTOD(), SET DECIMALS, TAN()

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