SectionS: Calculating in Complex Mode
The capability of the HP-15C to work with complex numbers
enables you to solve problems that extend beyond the realm of
real-valued numbers. On the following pages are several programs
that illustrate the usefulness of complex calculations—and the
Storing and Recalling Complex Numbers Using a Matrix
This program uses the stack and matrix C to store and recall
complex numbers. It has the following characteristics:
• If you specify an index greater than the matrix's dimensions,
the calculator displays Error 3 and the stack is ready for
• If the calculator isn't in Complex mode, the program activates
Complex mode and the imaginary part of the number is set to
• When you store a complex number, the index is lost, the stack
drops, and the T-register is duplicated in the Z-register.
• The "Store" program uses the  key, which is above the | STO |
key. The "Recall" program uses the |T| key, which is above the
Q] CLEAR [PRGM]
4 4 1 3
Enters 0 in real (and
Drops stack and has
a + ib in X-register.
Stores a and increments
indices (User mode).