Recent content by tomc612

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    MHB Solving SIR Model with Euler's Method

    And that's calculated by using the {I}_{n+1} formula with to obtain that result? and then the results for S and I are inputted to each of the formulas sequentially? And then the same for the R formula?
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    MHB Solving SIR Model with Euler's Method

    Thanks.. So to graph that function, you would then input the {S}_{1} result back into the formula. How do we produce the result when the formula requires the subsequent I value? Or does n value for I remain at a constant? Thanks
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    MHB Solving SIR Model with Euler's Method

    Hi, thanks for the info. To input values to the formulas.. with the example of S.. S(0)= {S}_{0} = 3 I(0) = I{S}_{0}= 5 h= 0.5 \beta=1 \gamma=2 Sn+1 = Sn +(h.-\betaSnIn) Sn+1 = 3 +(0.5.-1.3.5) Sn+1 = -4.5 Is that right? Thanks
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    MHB Solving SIR Model with Euler's Method

    Question on SIR Model and using Eulers method for approximating a solution. Given the 3 ODEs of the SIR model dS/dt = -\betaSI dI/dt= -\betaSI - \gammaI dR/dt = \gammaI Ive been asked to produce in excel Eulers method for axproximate solutions. Given some initial values for S(0) and I(0) as...
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    MHB Finding Matrix D Without Calculating P Inverse: Help Appreciated!

    Hi, got a question I'm stuck on.. Write down a matrix P which will diagonalise A and write down the corresponding diagonal matrix D, where D = P^-􀀀1AP. You do not have to calculate P^-1 Ive got all the eigenvalues and eigenvectors for A, and thus have the Matrix P, which has a determinant of...
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    MHB So, the car takes approximately 8.43 seconds to travel 100 meters.

    Hi, yeah really struggling with this one. So as its listed as a differential application, I've assumed there would be a First or Second Order differential to apply. if a(t) = t just doesn't seem to be a lot to go on. I can only think of integrating a(t) and then solving for t with the second...
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    MHB Related rates and differential

    so do we need to bring the Volume formula back into represent V and R if V =4/3pi.r^3 then r = (3V/4pi)^1/3r0=-kt +c (3V/4Pi)^1/3 =-kt+c is that the right path? Thanks
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    MHB So, the car takes approximately 8.43 seconds to travel 100 meters.

    hi, anti derivative of a(t) = 1/2at^2 anti-derivative of 1/2at^2 = 1/6at^3 which doesn't look like any of the kinematic equations. Still puzzled by this one as S= S(i) + V(i)+ 1/2at^2 which the derivative will give you a(t). Then solve with S = 100m Any advice appreciated Thanks
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    MHB Related rates and differential

    So, dr/dt = -k dr = -k.dt intergral dr = integral -k.dt r = -kt + c 0 = -kt +c Still not sure that's it, or should it be that the integral of -k.dt is -1/2k^2t Thanks
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    MHB So, the car takes approximately 8.43 seconds to travel 100 meters.

    Hi, another question I am having trouble with so my thought at the moment is to integrate a(t), which results in 1/2at^2 which is the kinematic equation for distance and then solve for the equation to equal 100. Just doesn't seem right to me and possibly too easy a solution.. think I am...
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    MHB Related rates and differential

    Hi, need some help on the following question. Just want to check on part a on the followingv=4/3\pi.r^3 dv = 4\pi.r^2 dr dv/dt = 4\pi.r^2 dr/dt dr/dt = (dv/dt)/ 4\pi.r^2 dr/dt = (-KA)/4\pi.r^2 dr/dt= -K part B need some help Thanks Tom
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    MHB Crank/Piston Motion: Understanding dB/dt, dB/dθ & d2B/dT2

    Sorry, the question should read:
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    MHB Crank/Piston Motion: Understanding dB/dt, dB/dθ & d2B/dT2

    Hi, Also need some help on a following question to this same problem. need work on optimisation for the values of A+B I tried optimising by implicit differentiation of a right and angled triangle, however the values I get are out side of the given range 12. we change the values of a and c...
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    MHB Crank/Piston Motion: Understanding dB/dt, dB/dθ & d2B/dT2

    Hi Thanks for the help, glad to see I wasn't too far off. One thing for the formula for B, i reached the formula by creating 'h' to represent the height of the joint of A+C, and then split B in B1 and B2 at h to create to right angle triangles. B=B1 + B2 B1 = Acos\theta B2 = \sqrt{C^2 -h^2} h...
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    MHB Crank/Piston Motion: Understanding dB/dt, dB/dθ & d2B/dT2

    Hi, Looking for some help on a crank/piston motion equation.. If a crank rotates counter clockwise measured in Radians/sec -as d\theta/dt = K T = time in secs The arms of the crank A and B are fixed and B is the stroke length with \theta as the angle between A and B So far I've got that B =...
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