TeenHelp
Support Forums Today's Posts

Get Advice Connect with TeenHelp Resources
HelpLINK Facebook     Twitter     Tumblr     Instagram    Hotlines    Safety Zone    Alternatives

You are not registered or have not logged in

Hello guest! (Not a guest? Log in above!)

As a guest on TeenHelp you are only able to use some of our site's features. By registering an account you will be able to enjoy unlimited access to our site, and will be able to:

  • Connect with thousands of teenagers worldwide by actively taking part in our Support Forums and Chat Room.
  • Find others with similar interests in our Social Groups.
  • Express yourself through our Blogs, Picture Albums and User Profiles.
  • And much much more!

Signing up is free, anonymous and will only take a few moments, so click here to register now!


Education and Careers Work of any kind can get stressful at times. Ask in this forum if you need help with coursework, applications, and more.

Closed Thread
 
Thread Tools Search this Thread
  (#1 (permalink)) Old
ForeverAutumn* Offline
together, we are infinite.
Senior TeenHelper
*******
 
ForeverAutumn*'s Avatar
 
Age: 24
Gender: Female

Posts: 843
Blog Entries: 20
Join Date: January 5th 2009

Rational Root Theorem? - February 10th 2009, 12:57 AM

My math book doesn't explain it at all and I don't have any notes from class - can anyone help me with the rational root theorem?

The equation I'm stuck on:

x(to the fourth power) + 4x(cubed) - 3x(squared) - 14x - 8

I did the P/Q thing and used synthetic division, that brought me to
(x-2) (x[cubed] + 6x[squared] + 9x + 4

I've absolutely no idea where to go from here. Help? I know I need to factor down the equation so I can fit it into the quadratic formula, then find the roots from there but I've no idea how to get past the x cubed.



how could anyone ever tell you, you are anything less than beautiful?| PM Me
self-harm free since 06.10.11.
   
  (#2 (permalink)) Old
Hyper Sonic Offline
Banned
I can't get enough
*********
 
Hyper Sonic's Avatar
 
Gender: Male
Location: England

Posts: 2,374
Blog Entries: 23
Join Date: January 5th 2009

Re: Rational Root Theorem? - February 10th 2009, 02:43 AM

Well I guessed substitutes and found than -1 makes
x - 6x +9x + 4 equal 0 so this makes (x+1) a factor of x - 6x +9x + 4 so dividing through by (x+1) gives x + 7x + 4 = 0 which in turn has roots of [-7+sqrt(33)]/2 or [-7-sqrt(33)]/2
   
Closed Thread

Bookmarks

Tags
rational, root, theorem

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All material copyright 1998-2019, TeenHelp.
Terms | Legal | Privacy | Conduct | Complaints

Powered by vBulletin®.
Copyright ©2000-2019, Jelsoft Enterprises Ltd.
Search engine optimization by vBSEO.
Theme developed in association with vBStyles.