1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Projections on subspaces

  1. Jan 4, 2008 #1
    [SOLVED] Projections on subspaces

    1. The problem statement, all variables and given/known data
    I have some questions on this topic:

    1) If I have an orthonormal basis for a subspace U and I have a vector A, and I want to find the orthogonal projection of A onto U, then I use the expression written here:


    2) If I have found the orthogonal complement V to U, and I wish to find the projection of the vector A onto V, I can either:

    - use the expression in http://mathworld.wolfram.com/VectorSpaceProjection.html on the orthonormal set that spans V

    - or use A - proj(U)_A (the projection of A onto U)

    3) I don't know if this is "legal", but I would like to draw your attention to my question in: https://www.physicsforums.com/showthread.php?t=207060

    3. The attempt at a solution
    Can you guys confirm this? Sadly, in my book it is not written that well.

    Thanks in advance,

    sincerely Niles.
  2. jcsd
  3. Jan 4, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Yes, that's correct.
  4. Jan 4, 2008 #3
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Projections on subspaces