a)
Let be a linear map. Define , for
some , where . Is D a subspace? If not explain.
b)
Let H and V be subspaces of . Is a subspace? Is a subspace? Explain your answers.
I don't think D is a subspace...but I don't know why.
What does and represent? There is nothing in part a of the problem that talks about H and V...
Lastly, what exactly are subspaces?
Step by step process with some explanation would be really nice!
Thank you for your time!