ATN()
Abbreviation: A <SHIFT+T>
TYPE: FunctionNumeric
FORMAT: ATN(<number>)
Action: This mathematical function returns the arc tangent of
the number. The result is the angle (in radians) whose tangent
is the number given. The result is always in the range pi/2 to
+pi/2.
EXAMPLES of ATN Function:
10 PRINT ATN(0)
20 X = ATN(J)*180/ {pi} : REM CONVERT TO DEGREES
