Recent content by Clef

  1. C

    Undergrad Second Order DE - Need Help With Equation

    okay. I think I've sort of got a handle on this way. Would it be =A'cos4t +B'sin4t = 0 -A'4sin4t + B'cos4t = -292sin4t Then by equating coefficients and integrating =A' = 73 therefore A = -73t B' = 0 therefore B= 0 therefore the PS is -73tsin4t?
  2. C

    Undergrad Second Order DE - Need Help With Equation

    or is it sufficient to use i= Acos4t + Bcos4t for the solution for the particular solution of the whole DE? Because I read somewhere that for some reason you have to put i= t(Acos4t + Bsin4t) but this is very very confusing :'(
  3. C

    Undergrad Second Order DE - Need Help With Equation

    I'm really sorry. But I do not completely understand this method. Would it be the same as substituting y= tAcos4t+tbsin4t into the equation and then equating to get the PS?
  4. C

    Undergrad Second Order DE - Need Help With Equation

    Okay I've found my homogenous solution to be (e^-3t)(Acos4t + Bsin4t) I'm now attempting the particular solution by changing the original equation into the complex form: z'' + 6z' +25z = -292e^(i4t) And solving that. To be honest I am completely stuck where to go from here and my...
  5. C

    Undergrad Second Order DE - Need Help With Equation

    Hey Guys, I've been banging my head with this one for a few days now. I've done (a) and (b) but I'm yet to do (c) if someone could complete this for me or help me along the way that would be greatly appreciated. Thanks heaps!
    • Clef
    • Thread
    • Second order
    • Replies: 7
    • Forum: Calculus
  6. C

    First Order ODE problem (ipod battery)

    Also for my hours i got 10 and 12 hours respectively. But I am still unsure about the Bpod :'(
  7. C

    First Order ODE problem (ipod battery)

    Homework Statement Cappy McGreenhorn is looking to buy a new MP3 player. His primary concern is the battery life of the MP3 player. He has decided on either the aPod or the bPod. The percentage of battery life A(t) (after t hours) for the aPod is governed by: (100 - t2)dA/dt + 4tA = 0...
  8. C

    Complex Polynomial Solutions: z^4 + iz^3 - z^2 - iz + 1 = 0 | Polar Form

    okay, I understand how that is the expanded form. So would the solutions for part b) just be the polar forms of part a) divided by (z-i)? Which would in turn make it: (z5-a5)/(z1-a3) = z4-a2 = z4-1 ??
  9. C

    Complex Polynomial Solutions: z^4 + iz^3 - z^2 - iz + 1 = 0 | Polar Form

    Homework Statement (b) Using your answer to part (a), write down all complex roots of the polynomial z4 + iz3 - z2 - iz + 1: Homework Equations (a) Determine all of the complex solutions of z5 - i = 0: Write your answers in polar form with -pi < x < pi. The Attempt at a Solution...
  10. C

    Integration Notation Homework Answers

    Then the first anser would be E, as it within the boundaries, but negative because the lowest point is being taken as the highest when integrating? Is that correct, if you can understand my reasoning:S
  11. C

    Integration Notation Homework Answers

    Homework Statement or http://img.photobucket.com/albums/v245/lilblonderoxy/ibntergrate.jpg The Attempt at a Solution For the first question, i looked at the graphs and which one was above the other one. in the first intersection, g(x) is above f(x) so i assumed the first area solution would...
  12. C

    Calculating Volume of Cylinder w/ Fixed Dimensions on A4 Paper

    The maximum volume is: 607.3 cm^3
  13. C

    Calculating Volume of Cylinder w/ Fixed Dimensions on A4 Paper

    Homework Statement Explain why, using this outline for creating the cylinder, the volume of the cylinder is fixed for an A4 piece of paper (30x21) Homework Equations h=30-4R I really don't know how to approach this question, i know it has something to do with the radius and the height...
  14. C

    Inclined planes, mass' effect on final velocity

    air resistance, of course!:)
  15. C

    Inclined planes, mass' effect on final velocity

    Okay, so I've been working on an extended practical investigation. And I am a little stuck. Heres a brief overview: Using a ramp(always at the same angle to the horizontal), and a truck and a stopwatch, I've timed the amount of time it takes for the truck to reach the bottom of the ramp, with...