In further discussions, we will only talk about polynomials *in one variable*. This means that there is only a single variable in the polynomial expression, and we generally denote that single variable by *x* (or in some cases, *y* or *z*). This is just a matter of convention; we can choose any other letter we may like. Also, we will generally represent polynomial expressions by the following symbols:

\[p\left( x \right),\,\,q\left( y \right),\,\,r\left( z \right),\,\,{\rm{etc}}{\rm{.}}\]

Some examples:

\[\begin{align}&p\left( x \right):a{x^2} + bx + c\\&q\left( y \right):3{y^3} + 2{y^2} + y\\&r\left( z \right):1 + z + {z^2} + {z^3} + {z^4}\end{align}\]

Note that we have used the colon sign **:** to specify the polynomials above. Whenever we have to define a polynomial, we will use the colon sign.