This is an archived, read-only copy of the United-TI subforum , including posts and topic from May 2003 to April 2012. If you would like to discuss any of the topics in this forum, you can visit Cemetech's
Technology & Calculator Open Topic subforum. Some of these topics may also be directly-linked to active Cemetech topics. If you are a Cemetech member with a linked United-TI account, you can link United-TI topics here with your current Cemetech topics.
Math and Science =>
Technology & Calculator Open Topic
| Author |
Message |
|
Brazucs
I have no idea what my avatar is.
Super Elite (Last Title)
Joined: 31 Mar 2004
Posts: 3349
|
 Posted: 28 Sep 2005 06:35:42 pm Post subject: |
|
|
| Anyone know? |
|
| Back to top |
|
|
DarkerLine
ceci n'est pas une |
Super Elite (Last Title)
Joined: 04 Nov 2003
Posts: 8328
|
| Posted: 28 Sep 2005 07:58:43 pm Post subject: |
|
|
Translating the math into normal language:
We need to find a number, call it X because I'm too lazy to find that greek letter, such that if x is less than X away from 2, then 1/x is less than .2 away from .5
First, I'd like to mention a little inaccuracy in the wording. You can just say 0 as the answer... whenever X is less than 0 away from 2 (which never happens!), anything can be true. (Any conclusion follows from a false statement). However, for fun, let's pretend the problem says what it meant to say: the largest X for which that is true.
The graph shows us that 1/x is less than .2 away from .5 if it is in the range (0.3, 0.7). If 0.3 < 1/x < 0.7, then 10/7 < x < 10/3 (as also seen from the graph).
So what is the largest X such that any x in the range (10/7, 10/3) is less than X away from 2? 2 - 10/7 = 4/7. 10/3 - 2 = 4/3. The former is smaller, so it makes for a stronger condition. Then X is 4/7: thus, any x that is less than 4/7 away from 2 will be in the range (10/7, 18/7) which is a subset of (10/7,10/3), satisfying the condition.
Indeed, suppose we chose a greater value for X. Then 10/7 would be less than X away from 2, but the condition is not satisfied for 10/7. So X can't be greater than 4/7.
Your answer is: 4/7.
Hope I explained myself clearly. |
|
| Back to top |
|
|
Raster
Active Member
Joined: 17 May 2004
Posts: 529
|
| Posted: 28 Sep 2005 08:24:34 pm Post subject: |
|
|
| I need to take math again, I hate this dang 4 blocks first semester, and 4 blocks the next... |
|
| Back to top |
|
|
DarkerLine
ceci n'est pas une |
Super Elite (Last Title)
Joined: 04 Nov 2003
Posts: 8328
|
| Posted: 28 Sep 2005 08:28:29 pm Post subject: |
|
|
| Indeed, block schedules are awful. Good thing I go to a school that has normal schedules unlike all the others around me. |
|
| Back to top |
|
|
Brazucs
I have no idea what my avatar is.
Super Elite (Last Title)
Joined: 31 Mar 2004
Posts: 3349
|
| Posted: 28 Sep 2005 09:22:07 pm Post subject: |
|
|
Yeah! 4/7 is what it says in the back of the book!
Thanks man... I finally understand it  |
|
| Back to top |
|
|
DigiTan
Unregistered HyperCam 2
Super Elite (Last Title)
Joined: 10 Nov 2003
Posts: 4468
|
| Posted: 28 Sep 2005 09:29:59 pm Post subject: |
|
|
Ah, I remember my block schedule...
Fall - forget math
Spring - forget english
Summer - forget everything!!! |
|
| Back to top |
|
|
|
Register to Join the Conversation
Have your own thoughts to add to this or any other topic? Want to ask a question, offer a suggestion, share your own programs and projects, upload a file to the file archives, get help with calculator and computer programming, or simply chat with like-minded coders and tech and calculator enthusiasts via the site-wide AJAX SAX widget? Registration for a free Cemetech account only takes a minute.
»
Go to Registration page
