PMUL performs polynomial multiplication of any degree (within limits of
available memory).


I originally wrote PMUL for the TI-85 almost three years ago (December
'92).  Essentially the two programs are the same but some things had to be
changed due to the way the TI-85 and the TI-82 implement list names and
variable names.


PMUL performs polynomial multiplication for polynomials of any degree.
The coefficients of each polynomial are entered in list form.  For
example the polynomial:

       X^4 + 8X^3 - X + 1

is represented by the list  { 1, 8, 0, -1, 1 }.   Note well that a
zero is in place of the missing "X^2" element as a place holder.

Running PMUL:
The program prompts you for two lists (L5 and L6).  One
list is the multiplicand and the second is the multiplier.
The first prompt is for L5.  Enter the list of coefficients for the
first polynomial and press ENTER.  Now enter the list of the coeffecients
for the second polynomial and again press ENTER.  What returns is the
coefficient product in list form.

Example:
Suppose you want to multiply the polynomials  X^3 - 4X^2 - 3X + 25
and 10X^3 + 5X  .

Execute PMUL and wait for the  "L5?" prompt.  Enter the list
{ 1, -4, -3, 25 } and press ENTER.

The second prompt, "L6?", will appear.  Enter the list  { 10, 0, 5, 0 }
and press ENTER.

The product is the list  { 10, -40, -25, 230, -15, 125, 0 }
representing the polynomial

       10X^6 - 40X^5 - 25X^4 + 230X^3 - 15X^2 + 125X + 0

Note that if the list is too large to view on the screen, it can be
scrolled to the left using the cursor keys.

I wrote this program as a utility and as compact as possible.  As such, I did not include user friendliness just basic prompts.  If you don't like it...change it...just give me credit where credit is due.


Variables used in the PMUL program:

        Lists: L5  the multiplicand coefficient lists.
               L6  the multiplier coefficient list.
               L4  a "dummy" list used for scratch work.
               L3  the product list.

        Reals: D   the size of L1.
               E   the size of L2.
               I,J loop counters.


Final note:
This program is Freeware and can be used in any fashion as long as I get
credit for creating them.  Thanks.

Any comments, questions, or suggestions for improvement can be directed to
rjhomard@tenet.edu

Richard Homard

