Talk:Chain rule

In line with the following,

$(f\circ g)'=(f'\circ g).g'\,$,

I would write for pedagogical reasons:

$z(y(x))\leftrightarrow z\circ y(x),$

and that

$(z\circ y)'=(z'\circ y).y'\,$

reads in Leibniz (traditional) notation,

${\frac {\mathrm {d} z(y(x))}{\mathrm {d} x}}={\frac {\mathrm {d} z(y)}{\mathrm {d} y}}\cdot {\frac {\mathrm {d} y(x)}{\mathrm {d} x}}.\,$.

What do you think? --Paul Wormer 09:50, 8 November 2008 (UTC)

I'ld be happy for you to add that, but I want to state the simple dz/dy.dy/dx not because I approve of it, but precisely because I don't: that is, I want to explain it. Richard Pinch 11:48, 8 November 2008 (UTC)