My Math Forum  

Go Back   My Math Forum > College Math Forum > Linear Algebra

Linear Algebra Linear Algebra Math Forum


Reply
 
LinkBack Thread Tools Display Modes
March 23rd, 2012, 03:32 PM   #1
Newbie
 
Joined: Mar 2012

Posts: 1
Thanks: 0

Vector Question

Hi I was wondering how I could go about doing the following question:

Three of the following represent the same line. Which one DOES NOT?

a) x = (0,0,2) + t(2,6,2)
b) x = (1,2,3) + t(2,6,2)
c) x = (1,2,3) + t(1,3,1)
d) x = (2,5,4) + t(1,3,1)

and the reasoning behind it? I have a few questions but I'm not sure I can post more than one at a time. Thank you!
Mazzy is offline  
 
March 23rd, 2012, 03:43 PM   #2
Global Moderator
 
Joined: May 2007

Posts: 6,770
Thanks: 700

Re: Vector Question

All 4 lines are in the same direction, so the question is which 3 have at least one point in common. Start by noticing b) and c) have the same start, so these must be 2 of the vectors. Now take the differences between starts (b vs. a or b vs. d) and see which are in the same direction as the common direction. You can see that the d) - b) start works, while the a) - b) does not.
mathman is offline  
Reply

  My Math Forum > College Math Forum > Linear Algebra

Tags
question, vector



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
3d vector question perfect_world Algebra 4 September 8th, 2013 02:49 AM
Vector question coachcft Linear Algebra 2 December 12th, 2012 03:40 AM
Vector Question suood Algebra 5 June 22nd, 2012 09:55 PM
Help with vector question please!!!!1 yas442 Linear Algebra 1 August 11th, 2011 03:36 PM
Vector Question suood Linear Algebra 0 December 31st, 1969 04:00 PM





Copyright © 2019 My Math Forum. All rights reserved.