Tell me a clear difference in Polynomial Expression,Rational Expression and Irrational Expression with example

Question

Easily and smoothly.I have to take exam tommorow

Answer 1

A polynomial expression is anything that's:

A constant
A power of a variable
A sum or difference or product of polynomial expressions

Almost anything you see around here with a request to factor is a polynomial.

A rational expression is anything that's:

A polynomial expression
A sum, difference, product, or QUOTIENT of rational expressions

Almost anything you see posted as a question with a request to "simplify" around here is a rational expression, UNLESS IT INCLUDES RADICALS (or trig functions)

"Irrational expression" is not a standard term, but I guess it's an expression that isn't rational. The square root of x-1 isn't rational, for example.