Recent content by TheBestMilk

  1. T

    Regression - AIC/SBC Comparison

    Never mind. I figured out I could estimate the log-linear model in levels which would allow me a comparison that fits with the generic linear regression. I couldn't figure out how to delete the post. Thanks anyways!
  2. T

    Regression - AIC/SBC Comparison

    I'm not sure if this is the right place for this question, but it was on the comparison between different model's AIC/SBC values. I ran a linear regression and got an AIC/SBC of .743/.768. When I ran the same regression in log-linear form I ended up with an AIC/SBC of -7.559/-7.534. My...
  3. T

    Double Integral Setup for Finding Area with Given Bounds

    Yep, you're right. Forgot to carry that negative sign through.
  4. T

    Double Integral Setup for Finding Area with Given Bounds

    Hey, Sorry it's been a few days. I had a friend in from out of town and a test in another class I was studying for. This is what I managed to come up with: \int^{u}_{0}\int^{y_{1}/2}_{0} dy_{2}dy_{1} + \int^{2u}_{u}\int^{y_{1}/2}_{y_{1}-u} dy_{2}dy_{1} = \int^{u}_{0}...
  5. T

    Double Integral Setup for Finding Area with Given Bounds

    Thank you very much. That makes perfect sense to me. Next time I'll draw the graph better to scale, which I think was throwing off where the y2 = y1 - u line was above the xaxis. Thanks!
  6. T

    Double Integral Setup for Finding Area with Given Bounds

    Ah, it seems I wrote the original bounds incorrectly. Sorry about that. The bounds are actually: 0≤y2≤1, 0≤y1≤2, and 2y2≤y1. Thanks!
  7. T

    Double Integral Setup for Finding Area with Given Bounds

    Homework Statement I have the bounds, 0≤y_{1}≤2, 0≤y_{2}≤1, and 2y_{2}≤y_{1}. I now have a line u=y_{1}-y_{2} and I'm trying to find the area such that y_{2}≥y_{1}-u. The integral comes down to two parts, the first of which I'm stuck on (when 0≤y1≤1). I'm pretty sure I have one way setup...
  8. T

    Partial with respect to ln(f(x))

    Homework Statement I'm working a problem, and I've come to taking the derivative with respect to ln(x): \frac{\partial ln(x^{c})}{\partial ln(p_{x})} Homework Equations ln(x^{c})=ln(p^{2}_{y}I)+ln(p_{x}+p_{y})-ln(p_{x})-ln(p_{y}) The Attempt at a Solution I've worked it out...
  9. T

    What are the steps for plotting a phase plane portrait?

    That makes a lot of sense now. Thank you for walking me through that!
  10. T

    What are the steps for plotting a phase plane portrait?

    Sorry about the confusing terms, but I did mean to say negative infinity as opposed to 0. Given the eigenvalues, the eigenvectors come out to y = 1/2*x and y = -1/2*x. I'm assuming I did the math right. That does make sense, I believe. I had thought that could be the case originally, but...
  11. T

    What are the steps for plotting a phase plane portrait?

    Well, the steady point, (2,2) will be a saddle solution. Not only because it can be seen due to the slopes in the quadrants, but also because the eigenvalues of the matrix formed by x',y' are +1/2 and -1/2 - thus giving us a saddle point. Given your dy/dx example, as x -> positive infinity...
  12. T

    What are the steps for plotting a phase plane portrait?

    Homework Statement Given x' = y - 2 y' = \frac{1}{4}x-\frac{1}{2} Draw the phase plane. The Attempt at a Solution First I found what I believe are the nullclines by taking x'=0 and y'=0. x' = 0 = y -2 so y = 2. y' = 0 = \frac{1}{4}x-\frac{1}{2} so x = 2. This...
  13. T

    First Order ODE Stability

    Homework Statement In the market for a certain good, the price p(t) adjusts continuously in the presence of excess supply or demand: \frac{dp}{dt} = F(D(p)-S(p)) where F(0) = 0, F'>0. Obtain the condition for stability of the equilibrium price p* in terms of the slopes D'(p*) and S'(p*), and...
Back
Top