Question

How to justify whether a polynomial is one variable?

Answer 1

Define the polynomial of one variable :

A polynomial is said to be written in standard form as

$P\left(x\right)={a_{n}x}^n+{a_{n-1}x}^{n-1}+......+a_{1}x+a_0$

A polynomial is said to be one variable if only one variable is present for example

1. $2x+5$
2. $x^2+5x+6$

On the other side if two variable present say

1. $xy+7$
2. $x{y}^2+y{x}^2+3$

We cannot say it a polynomial of one variable as there are two variables, $x$ and $y$.

Hence, by above observation we can justify polynomial of one variable.