Recent content by KevinD6

Hmm, that's what I thought at first too, but it seems that I was misinterpreting it the first time, I think it's saying how many ways can f(i) have some mapping to 1 and two, for example, f(1) = 1 and f(2) = 2, f(3) and f(4) can be whatever, but when I used that number, it didn't work. If I use...

Homework Statement Let A = {1, 2, 3, 4} and let F be the set of all functions from A to A. Let R be the relation on F defined by: For all functions f, g that are elements of F, (f, g) are only elements of R if and only if f(i) = g(i) for some i that is an element of A. Let the functions α, β...

Hmm, I just tried that but it seems that the variable 'y' cannot be used in my answer.

Oh yes, I'm sorry, for some reason I missed a negative sign on the 12 in the first row. I kind of get the relationship too, Y = [y1, y2, y3], where y2 = y1' and y3 = y2' if I'm not mistaken, I just don't see how this could be used to get a solution.

Hmm, I don't know, I've been reading the internet and the textbook but I can't find any clues on what it means. Also - I'm sure those are the eigenvalues, pretty sure at least, I did them by hand and then checked with wolfram.

Homework Statement Y' = [ -14 0 12 24 -2 24 16 0 14 ] Y Subject to the condition y_1 (0) = -6, y_2 (0) = 11, y_3 (0) = 8, find: y_1(t), y_2(t), y_3(t) Homework EquationsThe Attempt at a Solution This is more just to see if my answers are correct than anything, so I begin...

Wow! I can't believe I didn't see that, haha, thanks man. Much appreciated.

Homework Statement If y = y(t) is the solution of the initial value problem y' + (2 t + 1) y = 2 cos(t) y(0) = 2 What is y''(0)? Homework EquationsThe Attempt at a Solution Since this is a first order linear, I started out by finding the integrating factor so I can find what y is, and then...

Ahh, I see, it was just my ignorance about this method. Thanks guys! I hope to be posting here more in the future.

Homework Statement y'' + 9y = 3sin(3x) + 3 + e^{3x} Homework EquationsThe Attempt at a Solution This is my first post here so let me know if I've done anything wrong, I've been looking at questions here for a long time though ^^. So the problem asks me to solve for one particular solution...