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 Isomorphism question

  1. Mar 9, 2010 #1
    1. The problem statement, all variables and given/known data
    Let V be a vector space over the field of complex numbers, and suppose there is an isomorphism T of V onto C3. Let a1, a2, a3,a4 be vectors in V such that

    Ta1 = (1, 0 ,i)
    Ta2 = (-2, 1+i, 0)
    Ta3 = (-1, 1, 1)
    Ta4 = (2^1/2, i, 3)

    Let W1 be the suubspace spanned by a1 and a2, and let W2 be the subspace spanned by a3 and a4. What is the intersection of W1 and W2?

    2. Relevant equations

    3. The attempt at a solution

    In this problem, can we find numerical values for the intersection of the given two subspaces? It's obvious that the intersection would be a line passing through the origin, but given no numerical values of a1,2,3,4 in V, can we find a single vector that spans the line?
  2. jcsd
  3. Mar 9, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper

    It's not totally obvious it's a line. How did you show it's a line? If you can do that you can probably figure out how to show the intersection of W1 and W2 is span(v) where you can express v in terms of a linear combination of a1, a2, a3 and a4.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook