I'm having a problem to figure out what I'm doing is correct or not. I tried to find the streamline equation with a method I was taught by the textbook and vs another method I found on youtube by Simmy Sigma.


What I did:



which gives us



then I was looking for guides on youtube and stumbled across another method which does the following.


$$(\frac{dx}{xy}=\frac{dy}{y})xy\Longrightarrow dx=xdy$$




I'm confused to which of the answer is right, if one of them is even correct.If I was to draw this streamline by hand. I just change the value of $C=0,1,2...$ etc?

  • $\begingroup$ Shouldn't $dx = xdy$ go to $\int dy = \int \frac{1}{x} dx$? $\endgroup$ – Beta Decay Feb 25 '18 at 14:37

Your error occurs between here:$$dx=xdy$$ and here: $$-\int{xdx}=\int{dy}$$

  • $\begingroup$ is the first approach correct? $\endgroup$ – Sami Shafi Feb 25 '18 at 15:58
  • $\begingroup$ Yes. The two results should match. $\endgroup$ – Chet Miller Feb 26 '18 at 0:05

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