Use subs [tex]y=xv[/tex] to show that [tex](x^2+y^2)+2xy\frac{dy}{dx}=0, x>0[/tex] is [tex] x^3+3xy^2=k[/tex] where k is a constant.(adsbygoogle = window.adsbygoogle || []).push({});

I played around with this at school and if memory serves me correct i got something similar to [tex]\frac{dx}{dv}=\frac{-3}{2xv}-\frac{1}{2}[/tex] and after that i decided i wasnt on the right path and stopped. Need a little help here !

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# Cant solve diff-eq with substitution

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