HP 48gII - Manual (Page 170)

Page 4-8
Functions applied to complex numbers
Many of the keyboard-based functions defined in Chapter 3 for real numbers,
e.g., SQ, ,LN, e
x , LOG, 10 X , SIN, COS, TAN, ASIN, ACOS, ATAN, can be
applied to complex numbers. The result is another complex number, as
illustrated in the following examples. To apply this functions use the same
procedure as presented for real numbers (see Chapter 3).
Note: When using trigonometric functions and their inverses with complex
numbers the arguments are no longer angles. Therefore, the angular measure
selected for the calculator has no bearing in the calculation of these functions
with complex arguments. To understand the way that trigonometric functions,
and other functions, are defined for complex numbers consult a book on
complex variables.
Functions from the MTH menu
The hyperbolic functions and their inverses, as well as the Gamma, PSI, and
Psi functions (special functions) were introduced and applied to real numbers
in Chapter 3. These functions can also be applied to complex numbers by
following the procedures presented in Chapter 3. Some examples are shown
below: