Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Distributive Law and Vectors

  1. Mar 10, 2009 #1
    1. The problem statement, all variables and given/known data
    Let Vector a = (3, 4, 1), Vector b = (5, -2, 3) and Vector c = (0, 1, -3). Does Vector a × (Vector b + Vector c) = (Vector a × Vector b) + (Vector a × Vector c)


    2. Relevant equations

    a X (b+c)=(a X b)+(a X c)

    3. The attempt at a solution
    3 5
    4 -1
    1 0
    3 5
    4 -1
    1 0 Cross out the top 2 numbers and the bottom 2 numbers

    Draw 3 arrows going down and three arrows going up. Then subtract down minus up.

    for a X (b +c)

    (b+c) x=5+0=5
    y=-2+1=-1
    z=3-3=0
    Therefore (b+c=5,-1,0)

    a X (b+c)= (3,4,1) X (5,-1,0)
    =(15, -4, 0)
    According the answer this is wrong also I don't know what to do after this step?
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted