1.4 Rational Expressions

Question 1

What is a Rational Expression

Answer 1

A fractional expression where both the numerator and the denominator are polynomials

Question 2

What two things make the domain?

Answer 2

1. If there are factored expressions in the denominator, such as (x-2), then whatever makes those expressions 0 is not in the domain
2. If there is an even root sign with x in it, then the domain cannot be negative.

Question 3

How do you simplify rational expressions

Answer 3

Factor numerator and denominator then cancel common factors in the numerator and denominator

Question 4

How do you multiply/divide rational expressions?

Answer 4

If dividing, multiply by the reciprocal of the denominator. Cancel common factors in the numerator and denominator. Reduce if possible.

Question 5

How do you add/subtract rational expressions?

Answer 5

Get a least common denominator. Add/subtract in the numerator only and simplify.

Question 6

How do you rationalize a denominator.

Answer 6

Multiply the whole fraction by the denominator but with the sign switched. If it is just a root you do not need to switch the sign.