Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Dividing Polynomials
Name: Maria
Status: student	
Age:  N/A
Location: N/A
Country: N/A
Date: N/A


Question:
What use are there for learning to divide polynomials?



Replies:
Two reasons come to mind immediately: First remember, every number is a polynomial: For example, the number 4321 is: 4xN^3 + 3xN^2 + 2xN^1 + 1xN^0 where N (in our decimal system, N=10) so dividing polynomials is a generalization of ordinary numerical division. So that in itself is justification. However, I suspect that isn't what you wanted to know. The second reason is more "practical". Suppose you were posed with a homework problem: (6X^3 + 4X^2 - X + 1) is a curve, and you were asked to determine if that curve could be divided evenly into (2X^2 -1) parts, and how big will those equal parts be? I don't know the answer "by inspection" but it would be very easy to find out by dividing the first polynomial by the second and seeing if there is a remainder. If there is a remainder the answer is NO. If there is no remainder the answer is YES. If the answer is NO you could say how many equal parts there would be and how big a "piece" is left over.

Vince Calder


Maria,

I can think of several uses, one of the most important being problem-solving skills. When dividing one polynomial by another, we seldom have a preset formula to use. The procedure is fairly simple: factor both numerator and denominator, and then cancel common factors. This makes it appropriate for a wide variety of students. Doing a problem, however, requires reasoning skills. It cannot be done as simple arithmetic.

Although straight factoring can do something similar, polynomial factoring also prepares a student to interpret graphs. A ratio of polynomials is an excellent way to introduce zeroes and asymptotes, two very important concepts in graphical analysis. Being familiar with polynomial ratios beforehand can greatly help.

In addition, it is a good basis for introduction of limits. It relates the difference between a function that has a finite limit and a function with an infinite limit. It is a good example of a function that is missing just the one point rather than shooting up or down on a graph.

All these things, and more, are often introduced with a ratio of polynomials. To be familiar with them can be a great asset.

Dr. Ken Mellendorf
Physics Instructor
Illinois Central College


Maria,

Dividing polynomials is often done to simplify calculations that are used to calculate rates (two polynomials that describe things that vary with time and you are looking to see the relative change between both things -- especially with chemical "rates of reactions").

With the use of computers for modeling, the need to simplify calculations has gone away to some extent. But the skill is one that checks a true understanding of the principles of division and a student's ability to take a skill (such as long division) and expand that skill into a new realm (such as with polynomials instead of numbers).

I hope this helps! Thanks for your question.

Regards,

Todd Clark, Office of Science
US Department of Energy



Click here to return to the Mathematics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory