Math question - Polynomials

Pyro Pilots Lounge. For all topics *not* covered in other DBB forums.

Moderators: fliptw, roid

Post Reply
User avatar
Thenior
DBB Captain
DBB Captain
Posts: 667
Joined: Wed Oct 06, 2004 9:40 am

Math question - Polynomials

Post by Thenior »

Hey guys and gals,

Have a quick math question.

I have this math problem:

| x^-2y | ^-2
|x^-3y^5|

Or if you prefer to have it written out correctly:

Code: Select all

((x^-2y)/(x-3y^5))^-2
Here is the conclusion I came to:

1) Distribute

Code: Select all

^-2
this would equal:

Code: Select all

x^4 y^-2 / x^6 y^-10
2) Flip negative exponents. This would equal:

Code: Select all

x^4 y^10 / x^6 y^2
3) Subtract denominator exponents from numerator. This would equal:

Code: Select all

y^8 / x^2
Is my logic sound? This was on some homework I have, and none of the text went over this specific type of problem.
User avatar
fliptw
DBB DemiGod
DBB DemiGod
Posts: 6459
Joined: Sat Oct 24, 1998 2:01 am
Location: Calgary Alberta Canada

Re: Math question - Polynomials

Post by fliptw »

is it x^2-2y or x^(-2y)?

note: (x+1)^2 != x^2+1
User avatar
snoopy
DBB Benefactor
DBB Benefactor
Posts: 4435
Joined: Thu Sep 02, 1999 2:01 am

Re: Math question - Polynomials

Post by snoopy »

If your original equation is this:
math.JPG
math.JPG (2.04 KiB) Viewed 625 times
I think you did it correctly. Next time, use "*" signs and more parentheses to denote multiplication and what's being raised to what power, otherwise, your equation could read like this, which is a different beast:
math2.JPG
math2.JPG (1.99 KiB) Viewed 625 times
Arch Linux x86-64, Openbox
"We'll just set a new course for that empty region over there, near that blackish, holeish thing. " Zapp Brannigan
User avatar
Thenior
DBB Captain
DBB Captain
Posts: 667
Joined: Wed Oct 06, 2004 9:40 am

Re: Math question - Polynomials

Post by Thenior »

Sorry snoopy - thanks for the info and help!
User avatar
snoopy
DBB Benefactor
DBB Benefactor
Posts: 4435
Joined: Thu Sep 02, 1999 2:01 am

Re: Math question - Polynomials

Post by snoopy »

It's all good. When/if you get into using computer programs to solve stuff for you, you can get messed up. I'm usually really crazy about parenthesis in excel, just to make sure that it performs the correct operations on the correct items.
Arch Linux x86-64, Openbox
"We'll just set a new course for that empty region over there, near that blackish, holeish thing. " Zapp Brannigan
User avatar
Burlyman
DBB Admiral
DBB Admiral
Posts: 1275
Joined: Sun Oct 16, 2005 5:47 pm
Location: right behind you

Re: Math question - Polynomials

Post by Burlyman »

These are rational functions, not polynomials. Just sayin'. :P
User avatar
Top Gun
DBB Master
DBB Master
Posts: 8100
Joined: Wed Nov 13, 2002 3:01 am

Re: Math question - Polynomials

Post by Top Gun »

Um...they're rational polynomials, chief. :P
User avatar
Foil
DBB Material Defender
DBB Material Defender
Posts: 4900
Joined: Tue Nov 23, 2004 3:31 pm
Location: Denver, Colorado, USA
Contact:

Re: Math question - Polynomials

Post by Foil »

Yep, they're simply rational polynomial expressions at this point.
Post Reply