Recent content by mycroft

function out = rotatex(angle, in) m=[1 0 0 0; 0 cos(angle) -sin(angle) 0; 0 sin(angle) cos(angle) 0; 0 0 0 1]; out = m*in; And the call: >> out = rotatex(in, pi/4); ? Error using ==> horzcat CAT arguments dimensions are not consistent. Error in ==> rotatex at 2 m=[1 0 0 0; 0...

Yes, it's not closed downward. I think my mistake was imagining adding x \in A and y \in B as x_n + y_n thus causing O* to cancel the elements of A < 0. Am I right in assuming now that it is the set of each element x \in A added to all y \in B . Is it because Q is dense (and we...

Sorry to jump into this but actually I'm going through the same proof and I don't get this. -(q-p) in 0* I understand as some negative rational in the set of all negative rationals but the jump from there to saying A \subset A + 0* I just can't follow and the more I think about it the worse it...

thanks, ment to say 'or simply that it's a wave solution?', but yea I see now!

but will that prove it's a plane wave solution or simply that it's a solution? It was an exam question and that seems a little easy, but perhaps I'm just making things difficult for myself...

the latter, show that it is a plane wave solution for the wave equation, not derive a general solution. Thanks

I'm hoping that someone can descripe to me the steps involved in showing E = (Ex,Ey,0),where Ex=f(z-ct)+g(z+ct) and Ey=F(z-ct)+G(z+ct),is a plane wave solution to the wave equation (∇^2)E-[1/(c^2)](∂^2)E/∂(t^2) = 0 maxwell's wave equation if it's impossible to reat that!