Recent content by GreenGoblin

  1. GreenGoblin

    MHB Continuity and differentation.

    what has that got to do with anything? i already don't like you.
  2. GreenGoblin

    MHB Continuity and differentation.

    right but the function is defined as 0 at (0,0). so it has to be continuous as lim 0 = 0, and f(0,0) = 0 ?? :s I am stuck because it seems trivially true.
  3. GreenGoblin

    MHB Continuity and differentation.

    huh?i posted a pica.of the problem. that can't be the answer because this is not x, this is (x,y) so the answer has to be as much to do with y as x.
  4. GreenGoblin

    MHB Continuity and differentation.

    I am attaching a pico of the question as I don't think of how I can adequately write this up with text and symbols. Ok, so, I have one problem in my find. I know that it is continuous, if the limit as it approaches the point (in this case (0,0) = the function evaluated at that point). BUT, we...
  5. GreenGoblin

    MHB Unit tangent vector and equation of tangent line to curve

    Hi, thanks for your reply. So how can I express this? do i solve the derivatives at pi/2? I get (1, pi, -1). What can I do with this? I am really bad at this topic and I don't know where to go with it. What part of the question is this the solution for? I don't even know. I need a 'unit tangent...
  6. GreenGoblin

    MHB Unit tangent vector and equation of tangent line to curve

    "find a unit tangent vector and the equation of the tangent line to the curve r(t) = (t, t^2, cost), t>=0 at the point r(pi/2)." NOW, what I don't get is, how is that a curve? This is not like the example I have studied and I don't really get the question. So I don't know where to start. Once I...
  7. GreenGoblin

    MHB Cannot isolate y (first order quadratic DE?)

    One point: have I not made a mistake with the coefficient -1/10 on the LHS, should it not be -10? Since it is in the denominator.
  8. GreenGoblin

    MHB Cannot isolate y (first order quadratic DE?)

    What you just did is absolutely world class, I am going to work through and get an understanding, see if I get stuck again. Just want to say thanks a lot for now that gives me a lot to go with!
  9. GreenGoblin

    MHB Cannot isolate y (first order quadratic DE?)

    Thanks for your reply, using the method you said I lead to: \frac{-1}{10}\frac{dy}{(y-5)^{2}-16}= dx. IS this useful? How can I make it into partial fractions as you say?
  10. GreenGoblin

    MHB Cannot isolate y (first order quadratic DE?)

    I am required to solve two versions of the similar equation for y(x). I think this would be called a quadratic first order differential equation, but I don't even know if that is the correct name: 1)\frac{dy}{dx}=y - \frac{y^{2}}{10} - 0.9 2)\frac{dy}{dx}=y - \frac{y^{2}}{10} - 5 Confidence...
  11. GreenGoblin

    MHB Is the Expression Dimensionally Consistent?

    Yes I noticed that the 2nd term is just ma = F but multiplied by an additional l which makes it inconsistent. I thank you for your help and I am confident with this question now. I decided to accept delta as a length, it makes more sense that way. Gracias.
  12. GreenGoblin

    MHB Is the Expression Dimensionally Consistent?

    Hi, thanks a lot. In the second, we have two terms. I take it both would have to be consistent? I.e. then the RHS would be 2 x (whatever) which has dimension of (whatever). I get that the first term is consistent, but the 2nd is not.. if g has the dimension of acceleration which I believe is...
  13. GreenGoblin

    MHB Is the Expression Dimensionally Consistent?

    Which of the following are dimensionally consistent: U = \frac{EA\delta^{2}}{2\ell}, F = \frac{EA\delta}{l} + mg\ell. Right so. I get the concept, but the thing is I don't have (nor do I know where to find) expressions for each of these components. A is area so that is L^{2}. E is a 'pressure'...
  14. GreenGoblin

    MHB What is the geometric interpretation of a \centerdot c = 0?

    You know I have tendency to overcomplicate things. Sometimes I cannot accept the simplest answer because subconsciously maybe I suspect I am being asked a little more than I really am. Thank you very much you've been very helpful. I could get that far for sure, but I suspected I had to use a few...
  15. GreenGoblin

    MHB What is the geometric interpretation of a \centerdot c = 0?

    Thanks a lot. Thanks a lot. A complete mess.. and nothing really meaningful at all. Other putting it in directly, \lambda(a \centerdot c) + \frac{1}{|a|^{2}}(a \times b) \centerdot c = \alpha. I can't go further.
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