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Differential Equations

1.jpg

"need help".
I await the Laplace transform solution with eagerness, not that I will understand any of it.

Spoiler

y = 0.5 ( x - dx/dt )

dy/dt = 0.5 ( dx/dt - d2x/dt2 ) = 5x - y

dx/dt - d2x/dt2 = 10 x + dx/dt - x

etc....
Reply 3
Avatar for TeeEm
TeeEm
OP
19
Original post by 16Characters....
I await the Laplace transform solution with eagerness, not that I will understand any of it.

Spoiler



I got different
Original post by TeeEm
I got different


How different, have I screwed up my coefficients or is my entire form wrong?
Original post by 16Characters....
How different, have I screwed up my coefficients or is my entire form wrong?


:naughty:

:spank:
Reply 6
Avatar for TeeEm
TeeEm
OP
19
Original post by 16Characters....
How different, have I screwed up my coefficients or is my entire form wrong?


the form is correct but I have different coefficients
Reply 7
Avatar for Zacken
Zacken
22
Original post by TeeEm


"need help".


I get x=−cos⁡3t−53sin⁡3t\displaystyle x = -\cos 3t - \frac{5}{3}\sin 3t?
Reply 8
Avatar for TeeEm
TeeEm
OP
19
Original post by Zacken
I get x=−cos⁡3t−53sin⁡3t\displaystyle x = -\cos 3t - \frac{5}{3}\sin 3t?


yeah

I am off for my daily walk for an hour ...
see if you get the y
Reply 9
Avatar for Zacken
Zacken
22
Original post by TeeEm
yeah

I am off for my daily walk for an hour ...
see if you get the y


Enjoy!

Original post by 16Characters....
How different, have I screwed up my coefficients or is my entire form wrong?


You probably made a slight slip up when plugging in the values. dx/dt at t = 0 is -5.
Original post by Zacken
Enjoy!



You probably made a slight slip up when plugging in the values. dx/dt at t = 0 is -5.


Original post by TeeEm
the form is correct but I have different coefficients


Zacken is correct about my mistake, for the sake of neatness I wrote the general solution as 2y = ... but forgot about the 2 when substituting for y(0). I now have the same as him for x (and presumably y also).
Original post by Zacken
Enjoy!



You probably made a slight slip up when plugging in the values. dx/dt at t = 0 is -5.


its le duck/zack attack btw
but ill keep trolling @physicsmaths cuz its funnyyynynynynnynynynynynyynynyn6yygerbsjgfi48wouqe098ud!!!!!!!!!!!!!
Reply 13
Avatar for TeeEm
TeeEm
OP
19
Original post by TeeEm
1.jpg

"need help".


I managed to solve it ...
1.jpg418.4KB
2.jpg346.0KB

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