sought

  1. M

    INtuition sought about systems of first /second order diff equations

    Hi, I wonder if someone can give me some insight into the following, especially by way of geometric intuition. In solving a systems of first order differential equations, say \dot{x} = 3x + 2y \dot{y} = x + 4y I read that the systems of linear equations derived from this i.e...
  2. W

    Mathematica / Calculus Consultant Sought

    I am a new Mathematica user and have stumbled into a bit of a bind. My attempt to learn Mathematica and regain long lost calculus skills has been frustrated by an unexpected stream of other work responsibilities. I’m rolling up on a deadline that I will notbe able to meet and would like to...
  3. W

    Mathematica / Calculus Consultant Sought

    I am a new Mathematica user and havestumbled into a bit of a bind. Myattempt to learn Mathematica and regain long lost calculus skills has beenfrustrated by an unexpected stream of other work responsibilities. I’m rolling up on a deadline that I will notbe able to meet and would like to...
  4. K

    Assistance sought on how to go about solving graphing problem.

    The text asks: Find the possible slopes of a line that passes through (4,3) so that the portion of the line in the first quadrant forms a triangle of area 27 with the positive coordinate axes. I know that the equation for finding the area of a triangle is \frac{1}{2}bh. How do i go about...
  5. D

    Expert mathematicians sought... Headache & a half...

    I will endevour to explain this as best as I can... Thanks for your help in advance everyone! I work in an industry that analyses surveys sent from customers. Surveys can only be positive or negative. (Simple as that really). Now we have a site target to reach 90% positive. As a constant...
  6. G

    Integral sought for: C/x * exp(-1/2 [x-m/s]^2)

    I am trying to find a closed-form expression for the following integral: \int_{a}^{b}\frac{C}{x}exp^{-\frac{1}{2}(\frac{x-\mu}{\sigma})^2}dx with 0<a<b Neither Maple nor Mathematica will give a ready answer. If I put \mu to 0, Maple gives me...
  7. J

    Non computational proof sought

    Suppose you seek the smallest circle that can contain 11 non-overlapping unit disks. The solution to this problem is known, but the curious thing is that there are two different arrangements that give exactly the same radius for the circumscribing circle. Here is a picture of them: It is far...
  8. D

    Rotated ellipse equation sought

    I'm looking for a Cartesian equation for a rotated ellipse. h is x-koordinate of the center of the ellipse. k is y-koordinate of the center of the ellipse. a is the ellipse axis which is parallell to the x-axis when rotation is zero. b is the ellipse axis which is parallell to the y-axis...
  9. I

    [SOLVED] Help on statistical probability sought

    Hi all, I hope today finds you well and in good spirits. I have joined the forum in the hopes of trying to resolve a complex statistical issue (at least for me). Here is the question that I need your help with. What is the statistical probability of three women (all seniors) in a...