# Atan2s; Atanh - HP 48gII Advanced User's Reference Manual

Graphing calculator.

Access:
Flags:
Principal Solution (–1), Numerical Results (–3), Angle Mode (–17, –18)
Input/Output:
ACOS, ASIN, ISOL, TAN

## ATAN2S

CAS:
Transform expressions by replacing atan(x) with asin(x/√(x^2+1)).

### ATANH

Type:
Analytic Function
Description: Arc Hyperbolic Tangent Analytic Function: Returns the inverse hyperbolic tangent of the
argument.
For real arguments |x| > 1, ATANH returns the complex result obtained for the argument (x,
0). For a real argument x=±1, an Infinite Result exception occurs. If flag –22 is set (no error),
the sign of the result (MAXR) matches that of the argument.
The inverse of TANH is a relation, not a function, since TANH sends more than one argument
to the same result. The inverse relation for TANH is expressed by ISOL as the general solution;
The function ATANH is the inverse of a part of TANH, a part defined by restricting the domain
of TANH such that:
( Àis the left-shift of the Ukey).
Level 1/Argument 1
z
'symb'
ATANH(Z)+ *i*n1
Full Command and Function Reference 3-17
Level 1/Item 1
atan z
'ATAN(symb)'