Rational Expressions

A rational expression is a ratio of two polynomials in which the denominator is NOT a zero polynomial.

A zero polynomial is a specific type of polynomial where every coefficient (a number or constant value that is placed to and multiplies a variable in a math expression) is equal to 0, meaning it always evaluates to zero no matter what value you input for the variable.

Domain - is the set of all real numbers that can be used in place of the variable. Since division by zero is undefined, the only numbers that cannot be used in place of the variable are those that cause the denominator to have a value of zero.