Bernoulli Equation with weird integral

  • #1
TL;DR Summary
Differential equation ending with an integral that doesn't make sense
q2.png


Part of me thinks this is could be a u-sub b/c x^3's derivative is 3x^2, a factor of 3 off from what e is raised to...but it is not a traditional u-sub...any thoughts if this is a u-sub or by parts, and what u should be?


I know that there is more to solving the equation after this ( z = e^{1/(x^2)}(c_1+[insert integral from above], y = z^2) but i can't get to that without the integral above.
 
Last edited:

Answers and Replies

  • #2
I presume you're trying to solve
[tex]z'+Pz=Q[/tex]
I think you made a mistake:
[tex]-\int p(x)dx=-x^{2}[/tex] and not what you wrote down which was [itex]x^{-2}[/itex]. you could have cleverly spotted that multiplying throughout by [itex]e^{x^{2}}[/itex] the LHS is a derivative. Integrating the RHS can be written (with the appropriate change of variable (which you can find for yourself)):
[tex]\frac{1}{2}\int ue^{u}du[/tex]
 

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