HP 48gII - Manual (Page 169)

Page 4-7
Also, the result of function ARG, which represents an angle, will be given in
the units of angle measure currently selected. In this example, ARG(3.+5. i) =
1.0303… is given in radians.
In the next screen we present examples of functions SIGN, NEG (which shows
up as the negative sign - ), and CONJ.
CMPLX menu in keyboard
A second CMPLX menu is accessible by using the right-shift option associated
with the
1 key, i.e., ‚ß. With system flag 117 set to CHOOSE
boxes, the keyboard CMPLX menu shows up as the following screens:
The resulting menu include some of the functions already introduced in the
previous section, namely, ARG, ABS, CONJ, IM, NEG, RE, and SIGN. It also
includes function
i which serves the same purpose as the keystroke
combination „¥, i.e., to enter the unit imaginary number i in an
expression.
The keyboard-base CMPLX menu is an alternative to the MTH-based CMPLX
menu containing the basic complex number functions. Try the examples
shown earlier using the keyboard-based CMPLX menu for practice.