Qtr1_Module2_week2_Illustrating Rational_Expression

A rational algebraic expression is an expression that can be written in the form 𝑃 𝑄 where 𝑷 and 𝑸 are polynomials and 𝑸 must not be equal to 0 (Q ≠ 0).

In other words, a rational algebraic expression is an expression whose numerator and denominator are polynomials. From the previous activity, expressions formed in items 1,2 and 3 are rational algebraic expressions because the numerator and the denominator are both polynomials. On the other hand, expressions formed in items 4, 5, and 6 are not rational algebraic expressions because the numerator and denominator of the expressions are not polynomials. 

Here’s a useful checklist in identifying whether the expression is a rational algebraic expression:

 The expression must be in fraction form.

 The expression must have in its numerator and denominator a constant, a variable, or a combination of both, that are polynomial expressions.

 The expression must not have a negative exponent, a radical sign or a fraction exponent in the variable/s in both numerator and denominator.

Recall that the rational algebraic expression is a fraction containing polynomials in both numerator and denominator, provided that the denominator must not be equal to zero. The denominator cannot be zero because a division of 0 is undefined or meaningless. In rational algebraic expressions, you need to pay attention to what values of the variables that will make the denominator equal to 0. These values are called excluded values. How are you going to determine the excluded value/s in a rational algebraic expression?

Steps in Determining the Excluded Values:

(Study Tip: Just pay attention to the denominator of the expression to determine the excluded values.) Step

1: Let the expression in the denominator be equal to 0. Step

2: Solve the equation to determine the value/s of the variable. 

Here are the illustrative examples that will help you understand it better