Date: 7/10/96 at 18:20:45 From: Anonymous Subject: "Quadratic" Equation Why is a quadratic equation... quadratic? My math tutor asked me to find out and I have no idea where to start looking!
Date: 7/11/96 at 8:58:56 From: Doctor Paul Subject: Re: "Quadratic" Equation Good question! Quadratic equations are very important in math. A quadratic equation is one with form as follows: a*x^2 + b*x + c pronounced: A X squared plus B X + C An example of a quadratic equation would be: x^2 +2x + 1 In this particular case (and this case only!) a=1, b=2, and c=1 The fun comes when you set quadratic equations equal to zero and try to solve for values of x that satisfy the equation. There is a very famous formula that should help you solve quadratic equations but I'll let your tutor tell you what that is. One final note: Learn quadratic equations! They will appear in Algebra II, Pre-Calculus, all the way through Calculus and on into Differential Equations. You certainly want to learn them now before you fall behind! If you have any other questions, feel free to contact Dr. Math again. -Doctor Paul, The Math Forum Check out our web site! http://mathforum.org/dr.math/
Date: 7/14/96 at 21:14:58 From: Doctor Mike Subject: Re: "Quadratic" Equation Hello, I am another Dr. in the same mathematics clinic with Dr. Paul, who sent you an excellent answer to your quadratics question. One thing that makes mathematics so interesting is that there can be different answers to the same question. This usually comes from looking at the question in different ways, and the different answers can all be right. Dr. Paul and I consulted on your case yesterday, and you will be glad to know that both our fees are covered by insurance. I wanted to write back to you with a different answer. Dr. Paul's information will, I hope, be useful to you. His advice to be sure you learn quadratics well, including the quadratic formula, is right on the money. My point of view for this question is more oriented to the use of the words involved. Perhaps this is part of what you wanted. When a quadratic polynomial expression a*x^2 + b*x + c is set equal to zero the result is a quadratic equation. The reason that the word "quadratic" is used here is that the prefix "quad-" or "quadr-" in the English language usually means four (4) of something. This is because of our language's roots extending back to Latin, among other places. The simplest 4-sided figure is the square, and the highest power of x in a quadratic equation is x squared, or x to the power two (2). The word squared meaning power of 2 relates to the fact that the area of a square whose edge length is x is exactly x squared. Anyway, the word quadratic, with its quad- prefix, is used because of this connection between power 2 in the equation, and its relation to 4-sided squares. I hope both answers, together, cover what you were interested in. -Doctor Mike, The Math Forum Check out our web site! http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.