Recent content by jmarzouq

Let T:R^2 -> R^2 be the linear transformation that projects an R^2 vector (x,y) orthogonally onto (-2,4). Find the standard matrix for T. I understand how to find a standard transformation matrix, I just don't really know what it's asking for. Is the transformation just (x-2, y+4)? Any...

That's the thing. I'm at a loss as to how to do that exactly. The only thing I've been able to calculate the electric field for is point charges. Like I said, I've missed a couple of days and really have no idea what to do. I'd imagine you'd use Gauss's law, I just don't know how to go about...

Homework Statement A rod of length 2L has a charge -Q uniformly distributed over its left half and +Q uniformly distributed over its right half. Find E at point p a distance z above the center of the rod. Homework Equations E= 1/(4pi\epsilon_{0})∫dq/r(\hat{r}) dq=λdl where...

Ah, I see now. So A is equal to its own transpose so you can just substitute A back into the initial equation for A^T and get A^2 = A proving it's idempotent. I really appreciate the help!

Homework Statement Prove that if (A^τ)A = A, then A is idempotent. [Hint: First show that (A^τ)A = A^τ]Homework Equations N/AThe Attempt at a Solution I've gotten to the hint portion by taking the transpose of both sides, but have been unable to get that far past that. I've tried right side...