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

Vector dot product help!

  1. Mar 10, 2009 #1
    By evaluating their dot product, find the values of the scalar s for which the two vectors
    b=[tex]\hat{x}[/tex]+s[tex]\hat{y}[/tex] and c=[tex]\hat{x}[/tex]-s[tex]\hat{y}[/tex]
    are orthogonal.

    I understand that for the two vecotrs to be perpindicular their dot product must be 0. however im confused how to go about this problem as there are unit vectors.

    Any ideas are appreciated. thanks!
  2. jcsd
  3. Mar 10, 2009 #2


    User Avatar
    Homework Helper

    gday krugertown

    take the dot product & show me what you get...

    the unit vectors are generally orthonormal - meaning orthogonal & unit magnitude, this should help...
  4. Mar 10, 2009 #3
    so something like [tex]\hat{x}[/tex]-s[tex]^{2}[/tex][tex]\hat{y}[/tex]?
  5. Mar 10, 2009 #4


    User Avatar
    Homework Helper

    the results of a dot product should be a scalar not a vector quantity

    try writing out the whole dot product
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook