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# C4 - When to make C into ln|k| ?

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1. When separating variables when do you make C into ln|k|?
2. Bump
3. Example?
4. (Original post by ULTRALIGHT BEAM)
Example?
Just in general... When would you make C into ln k.... is that just whenever? does it matter?
5. I think I know what you're getting at...

Suppose you have a diff eq dy/y=2dx

integrate both sides lny=2x+c

y=e^(2x+c)

constant doesn't particularly matter, so you could write y=Ae^2x where c=lnA but that's redundant, really, just view A as the constant of integration.
6. Moved to maths.

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