Recent content by fred4321

I feel like I 'get' the dot product; my issue is, I can't seem to show it mathematically.

Dot product proof question? Hi, I'm having trouble understanding the proof of the dot product in three dimensions (not using the cosine rule approach). Here's what I have for the 2D proof: u = u1 i + u2 j v = v1 i + v2 j u.v = u1v1 + u2v2 u.v = |u| |v| cos(θ) => u1v1 + u2v2 = |u| |v|...

Thanks for the reply. What do you mean by, "let the program handle the shift"? Do you mean by changing adding k+n to the original equation so that it works out? Also, I know that I didn't say, but I'm actually doing this with MATLAB, I don't think that makes a difference. On know C++...

Hi, I am having trouble understanding how this works. I am giving the following: y[k+2] - y[k+1] + 0.24y[k] = f[k+2] - 2f[k+1]; y[-2] = 1, y[-1] = 2; f[k] = 0 for k < 0; f[k] = k for k >= 0; I would like to have a program compute the next values in the sequence, so, I need y[-2] = 1 to...