ATN
Format: var = ATN (expr)
Supported by: COMX BASIC V1.00, Floating Point BASIC 2.2, Pecom 32 BASIC, Pecom 64 BASIC 1.0 and 4.0, Quest Super BASIC 3.0, 5.0 and 6.0, RCA BASIC3 V1.1, Telmac SBASIC v 24.3
Similar commands: Quest Super BASIC 1.4: ATN
This function which has the same meaning as ARCTAN (expression) returns the angle (normally expressed in radians) whose tangent is equal to the value of the expression. This function is a floating-point function.
For example
PR ATN (1)
will print
.785399
since TAN (0.785399) = TAN PI/4 = TAN 45°