How to Simplify a Rational Function

In summary, a rational function is a mathematical expression written as a ratio of two polynomials. To simplify a rational function, you must factor the numerator and denominator and cancel out common factors. It is important to simplify for easier understanding, identifying asymptotes, and finding the domain and range. Common mistakes to avoid include canceling out non-common factors, forgetting to check for excluded values, and being careful with negative exponents and complex numbers. Not all rational functions can be simplified, so it is important to check for simplification opportunities before assuming.
  • #1
LoA
13
0

Homework Statement



u^2
---------------
u^2 - 4

Homework Equations



I am told that this is equal to

1+ 4/u^2 - 4

The Attempt at a Solution



No clue how these two are related. Factor out a u^2/u^2? But that alters the denominator. My next that is partial fraction decomp. Am I on track?
 
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  • #2
Use polynomial long division. Or, note that in the numerator,
[itex]u^2 = \left( u^2 - 4 \right) + 4[/itex].
 

What is a rational function?

A rational function is a mathematical expression that can be written as a ratio of two polynomials. It has the form f(x) = p(x)/q(x), where p(x) and q(x) are polynomials and q(x) is not equal to 0.

How do I simplify a rational function?

To simplify a rational function, you must first factor the numerator and denominator into their simplest forms. Then, you can cancel out any common factors between the two polynomials. Finally, rewrite the remaining expression in its simplest form.

Why is it important to simplify a rational function?

Simplifying a rational function can make it easier to understand and work with. It also helps to identify any potential asymptotes or undefined points. In addition, simplifying can make it easier to find the domain and range of the function.

What are some common mistakes to avoid when simplifying a rational function?

One common mistake is to cancel out terms that are not common factors. Another mistake is to forget to check for any excluded values in the simplified expression. It is also important to be careful when dealing with negative exponents or complex numbers.

Can all rational functions be simplified?

No, not all rational functions can be simplified. Some rational functions may already be in their simplest form, while others may have terms that cannot be factored. It is important to check for common factors and simplification opportunities before assuming the function can be simplified.

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