Some more Maths + Matlab/Wolfram Alpha queries

[Nick 50]

Firstly, could someone confirm I have got the correct answer please?

It's a 2nd Order Differential Equation with Resonance.

https://i300.photobucket.com/albums/nn6/ElScampio/BCFmaths1_zpsed1d87d0.png
https://i300.photobucket.com/albums/nn6/ElScampio/BCFmaths2_zps41b148e4.png
https://i300.photobucket.com/albums/nn6/ElScampio/BCFmaths3_zps86570270.png

I did try Wolfram Alpha which gave me an answer of:

https://i300.photobucket.com/albums/nn6/ElScampio/BCFWA_zpsf40ab561.png

ermmmmmm ok.

Secondly, can Matlab solve forced 2nd ODE's? If so, what do you input?

Most importantly I checked:
Is_the_answer_Potato.com And it said the answer is definitely NOT Potato.
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First bike: A GZ125 Lemon.......

[el_oso]

MATLAB will not be able to solve the equation exactly (as far as I'm aware)
you can however use ODE45, which is a fourth order Runge-Kutta method to solve it. Google the documentation on it. It's pretty well documented and easy to implement in MATLAB as long as you know how to reduce that equation into separate matrices. The 4th Order RK4 method is reasonably accurate.
How you would check if your solution is indeed the right solution is to plot a graph using ODE45 against your result
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Duke 390
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[Nick 50]

Thanks the_godfather. I've never really used Matlab to try and solve ODE's before. I will hunt around for info on ODE45 command. Thanks
____________________
Current Bikes: ZX7r 97 (Black Beauty), VFR400 NC24 (The banana)
Previous Bikes: Aprilia Tuono 03 (The Beast), CBR600f (97)
First bike: A GZ125 Lemon.......

[el_oso]

It is pretty well documented. If you have done programming before and are comfortable/capable of reducing that equation into several linear equations then it is very straight forward.
for example:

https://cdn.bikechatforums.com/files/codecogseqn__2_.gif

and using the substitution for dy/dt

https://cdn.bikechatforums.com/files/codecogseqn__1_.gif

and then solve the 2 equations simultaneously
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Duke 390
Previous: '05 XR125L | '96 XJ600S Diversion |'05 Suzuki GSXR1000 | '05 Honda CBR125-R | '97 YZF 600R Thundercat | '11 Honda CBR250
Car: Jeep Wrangler 4.0L

[lihp]

Sorry, but how do you get your formula like that?

What software generates those images?

[Nick 50]

[lihp]

the_godfather, seen a couple of people do it recently in the same format.

I only use Word 2003, so I don't think I could do it your way, it seems it was only added in 2007?

The maths side of my course is handwritten, but annoyingly, assignments are submitted electronically, and all typed for the Mech Engineering side, and thought it would be a nice way of laying out the math.

[el_oso]

That is done using an online latex editor. google laTex editor and there will be a plethora or results.

you can use word 2003. it called equation editor. Again, there is loads of documentation on it.
clicky for instructions on how to open equation editor in word 2003.

in equation editor when you want to insert special characters such as Psi, you can put the / before it. i.e.