Recent content by KevinL

Hmm. For most of the similar models that I've been dealing with, it was possible to write the "reaction functions" (the functions I wrote in my first post) in such a way that you could actually have X in the next period determined by X in the last period. The test for stability of the...

Sorry for getting back to you on this late, been busy! For the most part this is working as I would like. I put in: k0 = .6; x0 = .3; y0 = .1 ; w = 1; f[{k_, x_, y_}] := {-x - y + w, k*Sqrt[y/(-y + w)] - y, k*Sqrt[x/(-x + w)] - x} r = NestList[f, {k0, x0, y0}, 100]...

I have no programming experience and trying to get mathematica to do what I need it to do is frustrating. I have the following functions that I need to iterate. For notational purposes, k[t+1] is the value of K in the next period. w is a parameter. k[t+1] = -x[t] - y[t] + w x[t+1] =...

I feel like I'm doing this correctly but my professor gave us an answer that is different from what I'm getting. Composition of (12345)(12345) Reading right to left I get (13524) but the answer he gives is (135)(24) The odd thing is I'm getting the rest of these correct so I don't feel...

Intuitively that answer makes a lot of sense. Of course to minimize a cost function of this sort, production would need to be zero. And since we require production to be greater than zero, its unbounded. So perhaps it would be wise to include the entire profit function and maximize that...

For my economics/game theory thesis I need to optimize a function subject to an inequality constraint. maximize f(x1, x2) = 1/(x1+x2+y1+y2-w) subject to g(x1, x2) = x1+x2+y1+y2 < w This isn't particularly important, but the x and y variables are quantity of production by a firm. The objective...

I'm doing my economics thesis on game theory, and need to solve a system of nonlinear equations (these will be the reaction functions). Unfortunately, I have no idea how to solve it explicitly--indeed, I am a bit worried its impossible with the parameters. It is rather symmetric though. The...

Im trying it with induction. Let A be the set of all finite subsets of N Let an , n>=1 be a set of subsets of N each with cardinality of n. Claim: Any an is countable, so the union from n=0 to infinity of an is countable, and thus A would be countable. Prove by induction. basis: n=1, a1: N...

Homework Statement Show that the set of all finite subsets of N is a countable set. The Attempt at a Solution At first I thought this was really easy. I had A = {B1, B2, B3, ... }, where Bn is some finite subset of N. Since any B is finite and therefore countable, and since a union of...

Uhg, sorry. Thought I had google hyperlinked...

Google has my particular homework online. I am doing 1.5.6, 1.5.7, 1.5.8 On 1.5.6 a), I created a function f(x) such that {a} if x = a, {b} if x = b, {c} if x=c. This is 1-1 since each element of A gets mapped to something different. Its obviously not onto. Skipping down to 1.5.7, I need...

Sorry not sure how I missed that. The question is "Is L a linear map?" I think I MAY have it now. I need to show linearity by proving L(a+b+c+d)=L(a) + L(b) + L(c) + L(d) So, L(a+b+c+d) = a 2x2 matrix where each corner is (a + b + c + d) L(a) is a 2x2 matrix w/ each corner containing a...

Homework Statement Consider the map L from the space of 2x2-matrices to R given by: L([a b]) = a+ d ([c d]) For clarity, that's L(2x2 matrix) = a + d The Attempt at a Solution Im confused how any function of a matrix could possibly equal addition of two scalars, and thus have no...

Thanks guys, worked it out and the answer agrees with the back of the book :)

Homework Statement Find an equation of the plane that contains the lines given by: (x-1)/-2 = y - 4 = z and (x-2)/-3 = (y-1)/4 = (z-2)/-1 The Attempt at a Solution Not too sure about how to go about it. I believe these are the parametric equations for the lines: x = 1-2t...