Hi guys,
In one of my lecture notes examples on substitution methods for ODE's
I have a DE
dy/dx = (2y^4+x^4) / (xy^3)
It then says to use the substitution y=xv.
The next line then becomes
v+x dv/dx = (2(xv)^4+x^4) / (x(xv)^3)
Now I see on the right hand side the substitution y=xv.
what I don't understand is the LHS.
How did they go from dy/dx to v+x dv/dx ??
