HP -28S Manual page 33

You can move to the first catalog entry for a particular letter by press-
ing the letter key. Try 'T'.
IT]
I ~I I
CImmD_DHIIIIBEIE!mD
The first "T" command is the TAN function. If you press a symbol
(non-letter) key on the left-hand keyboard, the catalog moves to the
first catalog entry for that symbol. Try
"~".
The first
"~"
command is the
~
+
command. If you press a symbol
key on the left-hand keyboard, and no commands begin with that
symbol, the catalog moves to
+,
the first non-alphabetical command.
rn
11lIm1llll1l_1ImI1HI!IlI1!IIIiI1
Check the usage for
+.
USE
ftN'NuMber
1: Real NUMber
CImmD _ _ _ E!mD
This shows that you can add two real numbers. Check the next
combina tion.
NEXT
This shows that you can add real and complex numbers. Check the
next combination.
NEXT
~~ex
NUMber
1: Real NUMber
CImmD _ _ _ E!mD
This shows that the real and complex numbers can be in either order.
32 1: Getting Started