Just a quick question... I have the equation:
$\frac{dw}{dy} w^{-2}=0$
Is this separable? i.e. can I go :
$\begin{align} \frac{dw}{dy} w^{-2}&=0 \\[8pt] (w^{-2}) \,dw&=(0)\,dy \tag{*} \\[8pt] -w^{-1}&=A \end{align}$ and thus $w = B$ with $A,B$ being arbitrary constants with $B \not= 0$
Is this ok? The only thing I'm wondering about is the starred line... can I separate the equation like that with only a zero on the RHS?