could someone please please tell me how to integrate

dx/dt = (x^3).(e^t)

intial condition : x(1) = -4

this looks v.simple but trust me, its not!

:( help me out! aaaah...

thank you

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- Nov 3rd 2009, 11:49 AMmatlabnoobIntegrating IVP
could someone please please tell me how to integrate

dx/dt = (x^3).(e^t)

intial condition : x(1) = -4

this looks v.simple but trust me, its not!

:( help me out! aaaah...

thank you - Nov 3rd 2009, 11:53 AMartvandalay11
- Nov 3rd 2009, 11:56 AMmatlabnoob
- Nov 3rd 2009, 12:01 PMartvandalay11

$\displaystyle x(1)=-4$ so when t=1, x=-4

$\displaystyle

-\frac{1}{2(-4)^2}=e^1+c

$

$\displaystyle -\frac{1}{32}=e+c$

So $\displaystyle c=-e-\frac{1}{32}$

And the solution is

$\displaystyle -\frac{1}{2x^2}=e^t-e-\frac{1}{32}$

which can be combined or manipulated or whatever you wanna do but I'll leave it like that - Nov 3rd 2009, 12:07 PMmatlabnoob
thank you!=] woaah its that easy.... i spent 2 hourson this!!