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: Simple mutiplication vector problem

  1. May 20, 2010 #1
    1. The problem statement, all variables and given/known data

    if vector d1=3i-2j+4k and d2=-5i+2j-k then what is (d1+d2).(d1x4d2)? (period between brackets indicates "dot"

    2. Relevant equations

    mutiplication

    3. The attempt at a solution

    so i got d1+d2=-2i+0j+3k and d1x4d2=-24i-68j-16k
    what do i do next?
    is the answer (-2)(-24)+(0)(-68)+3(-16)?

    thanks!
     
  2. jcsd
  3. May 20, 2010 #2
    Yes that's correct, memorize how to calculate the vector product and dot product of vectors, its essential for physics.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook