Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Replies: 9   Last Post: Oct 18, 1999 10:23 PM

 Messages: [ Previous | Next ]
 Physics Boy Posts: 9 Registered: 12/6/04
Posted: Oct 17, 1999 4:33 PM

>If I have some nasty numbers in quadratic form, how do I factor and solve

>-4.9x^2+5.5x-105=0
>That factors to x(-4.9x+5.5) = -105

>What next??

You can "complete the square", by finding out what binomial squared
gives -4.9x^2 + 5.5x + A, where A isn't known.

Then, write the expression as this binomial squared, + A - A. Play
with this, and you find that the general solution to

ax^2 + bx + c = 0

is given by

-b +/- (b^2 - 4ac)^(1/2)
x = --------------------------
2a

- Physics Boy

http://www.ualberta.ca/~wdowler
ICQ# 24893016
AIM: FizikoBoy
XFW# 299792458, WM, S'sW, GMW, NRMTPB

Ray Stantz: You know, it just occured to me that we really haven't had
a successful test of this equipment.
Egon Spengler: I blame myself.
Peter Venkman: So do I.

Date Subject Author
10/17/99 Nick Marques
10/17/99 Wilson Figueroa
10/17/99 Physics Boy
10/17/99 dannyboy@here.com
10/18/99 Tom Davidson
10/18/99 Richard Carr
10/18/99 Tom Davidson
10/18/99 dannyboy@here.com
10/18/99 Tom Davidson
10/18/99 Kyle R. Hofmann