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Need help with Linear Combinations

  1. Mar 24, 2007 #1
    Hey all,
    im taking geometry and discrete mathematics at my school. Its a 12 U course. And im not doing as well as i would like in it. Im at about a 75, annd i want that to be around 85. So im looking to you guys for some help. If you guys wouldn't mind awnsering a few questions i have from my homework each night it would be greatly appreciated. The homework doesn't have to be handed in or anything just to improve my knowledge. Thanks.

    1. The problem statement, all variables and given/known data

    11) demonstrate that the three vectors u=(1,3,2) v=(1,-1,1) and w=(5,-1,4) are mutally perpindicular.

    12) if vector u=(5,-5,2) vector v=(1,8,-4) and vector w=(-2,-1,2) express vector x=(-3,6,8) in terms of vectors u v and w.
    2. Relevant equations
  2. jcsd
  3. Mar 24, 2007 #2

    D H

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    Staff Emeritus
    Science Advisor

    11) How do you know whether two vectors are perpendicular to one another?

    12) How would you attack a problem like this in general? In other words, what are the relevant equations?

    I am not being mean here. You would not learn much if I simply told you the answers. Show us some work and we will help you get past trouble spots.
  4. Mar 24, 2007 #3
    11) dot product=0, can i take the first two vectors and use the dot product to see if they are perpindicular, then the second two?
    12)my book is at my friends ill edit this when i get it.
    Last edited: Mar 24, 2007
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