HP 15c - Manual (Page 122)

122 Section 11: Calculating With Complex Numbers
Example: Add 2 + 3i and 4 + 5i. (The operations are illustrated in the stack
diagrams following the keystroke listing.)
Keystrokes Display
´ • 4
2
v 2.0000
Keys real part of first number
into (real) Y-register.
3
3
Keys imaginary part of first
number into (real)
X-register.
´ V 2.0000
Creates imaginary stack; moves
the 3 into the imaginary X-
register, and drops the 2 into the
real X-register.
4
v 4.0000
Keys real part of second number
into (real) Y-register.
5
5
Keys imaginary part of second
number into (real) X-register.
´ V 4.0000
Copies 5 from real
X-register into imaginary
X-register, copies 4 from real Y-
register into real X-register, and
drops stack.
+ 6.0000
Real part of sum.
´ % (hold) 8.0000
Displays imaginary part
(release)
6.0000
of sum while the % key is held.
(This also terminates digit entry.)
The operation of the real and imaginary stacks during this process is
illustrated below. (Assume that the stack registers have been loaded already
with the numbers shown as the result of previous calculations). Note that
the imaginary stack, which is shown below at the right of the real stack, is
not created until ´ V is pressed. (Recall also that the shading of the
stack indicates that those contents will be written over when the next
number is keyed in or recalled.)