We have recently learned how to solve polynomial equations in Matlab, now we are going to visit a trick that will help you learn how to do Division and Multiplication of polynomial using Matlab.

## Polynomial Division example

## Polynomial Multiplication example

## Matlab Polynomial

Multiplication of polynomial can be a very dreary task, so do division of polynomial. Matlab use the functions** conv** and **deconv** to help you do these tasks with the least commotion possible, and most importantly with the assurance to find the right result the quickest way *possible*.

Let get on some examples, those will help easily learn how to make use of **conv** (for multiplication) and **deconv** (for division).

### Example 1

The code

s=[1 4]; t=[1 4 -3]; conv(s,t)

Which returns

Rewritten, it gives the following

### Example 2

The code

c=[1 0 4]; u=[1 3]; [p,r]=deconv(c,u)% r is the remainder of the division

Which returns

Rewritten, it gives

### A bit of clarity

*Top-down conversion*. Here we simply need to indicate the coefficient and their position in the polynomial equation.

*Bottom-up conversion*. Here we need to read Matlab outputs and rewrite it the way it is supposed to be, and it goes like this.

Remember you need to put a zero, in case an order is not represented in the equation. *See example below*