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Good evening !

What would be the answer of : dx/dt * x2 = e2t
 It would be great of you to answer !

Thks and happy new year

 Dec 30, 2015

Best Answer 

 #3
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Thanks Guest, 

I just want to play too.    laugh

 

dxdtx2=e2tx2dxdt=e2tx2dxdtdt=e2tdtx2dx=e2tdtx33=e2t2+c1x3=3e2t2+c2x=[3e2t+c32]1/3

 

Last line has been edited.

 Jan 1, 2016
edited by Melody  Jan 1, 2016
 #1
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Solve the separable equation x(t)^2 ( dx(t))/( dt) = e^(2 t):
Integrate both sides with respect to t:
integral ( dx(t))/( dt) x(t)^2 dt  =   integral e^(2 t)  dt
Evaluate the integrals:
x(t)^3/3  =  e^(2 t)/2+c_1
Solve for x(t):
x(t) = -((-3/2)^(1/3) (e^(2 t)+2 c_1)^(1/3)) or x(t) = (3/2)^(1/3) (e^(2 t)+2 c_1)^(1/3) or x(t) = (-1)^(2/3) (3/2)^(1/3) (e^(2 t)+2 c_1)^(1/3)
Simplify the arbitrary constants:
Answer: | x(t) = -((-3/2)^(1/3) (e^(2 t)+c_1)^(1/3))           or x(t) = (3/2)^(1/3) (e^(2 t)+c_1)^(1/3) or x(t) = (-1)^(2/3) (3/2)^(1/3) (e^(2 t)+c_1)^(1/3)

 Dec 30, 2015
 #2
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+5

Oups I feel super dumb haha thanks !

 Dec 30, 2015
 #3
avatar+118696 
+5
Best Answer

Thanks Guest, 

I just want to play too.    laugh

 

dxdtx2=e2tx2dxdt=e2tx2dxdtdt=e2tdtx2dx=e2tdtx33=e2t2+c1x3=3e2t2+c2x=[3e2t+c32]1/3

 

Last line has been edited.

Melody Jan 1, 2016
edited by Melody  Jan 1, 2016
 #4
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You might want to take another look at that last line Melody.

Bertie

 Jan 1, 2016
 #5
avatar+118696 
0

Thanks Bertie,

I think it is better now ?

 

 Jan 1, 2016

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