Unsure how to treat y in this derivative/log problem Need to find the derivative of $h(y)= \ln(y^2 \cos y)$
Treating it like a normal variable like an x isn't working for me, the way we used y's in earlier problems where you get a y' in there doesn't seem right, so I'm not quite sure here. 

Mathematics is invariant under change of notation
Mathematics is invariant under change of notation
Mathematics is invariant under change of notation
You're doing something wrong if you treat that $y$ as differently than if it was an $x$ or a $\mu$ or small drawing of a house.
$$\frac{d}{dy}h(y)=\frac{2}{y}-\tan(y)$$ holds just as surely as it would if $y$ were $x$.
