Asosiy tarkibga o'tish

13.6-bo'lim : Zanjir qoidasi

8. Quyidagi vaziyat uchun \(\displaystyle \frac{{\partial w}}{{\partial t}}\) va \(\displaystyle \frac{{\partial w}}{{\partial u}}\) formulalarini aniqlang.

\[w = w\left( {x,y,z} \right)\hspace{0.5in}x = x\left( t \right),\,\,\,\,y = y\left( {u,v,p} \right),\,\,\,\,z = z\left( {v,p} \right),\,\,\,\,v = v\left( {r,u} \right),\,\,\,\,p = p\left( {t,u} \right)\]
Yechim

Ushbu hosilalarning formulasini aniqlash uchun bizga quyidagi daraxt diagrammasi kerak bo'ladi.

A tree diagram for the chain rule.  At the top is \(w\), which branches down to \(x\), \(y\) and \(z\).  From \(x\) there is a branch to \(t\); from \(y\) there are branches to \(u\), \(v\) and \(p\); and from \(z\) there are branches to \(v\) and \(p\).  Each \(v\) then branches on to \(r\) and \(u\) and each \(p\) branches on to \(t\) and \(u\).  The last row of derivatives uses subscript notation to keep the labels readable and the variables we are differentiating with respect to are colored.

Ushbu daraxt diagrammalarining ba'zilari juda chalkash bo'lishi mumkin. Biz har bir lotin uchun amal qilishimiz kerak bo'lgan novdalarni biroz aniqroq qilish uchun bizni qiziqtirgan o'zgaruvchilarni rangladik.

Bundan tashqari, shoxlarning oxirgi "qatori" bir-biriga biroz yaqinlashib qolganligi sababli, biz har bir filial bilan qaysi lotin bog'langanligini ko'rishni osonlashtirish uchun pastki lotin yozuviga o'tdik.

2-qadam

Mana bizdan topishimiz so'raladigan formulalar.

\[\frac{{\partial w}}{{\partial t}} = \frac{{\partial w}}{{\partial x}}\frac{{\partial x}}{{\partial t}} + \frac{{\partial w}}{{\partial y}}\frac{{\partial y}}{{\partial p}}\frac{{\partial p}}{{\partial t}} + \frac{{\partial w}}{{\partial z}}\frac{{\partial z}}{{\partial p}}\frac{{\partial p}}{{\partial t}}\] \[\frac{{\partial w}}{{\partial u}} = \frac{{\partial w}}{{\partial y}}\frac{{\partial y}}{{\partial u}} + \frac{{\partial w}}{{\partial y}}\frac{{\partial y}}{{\partial v}}\frac{{\partial v}}{{\partial u}} + \frac{{\partial w}}{{\partial y}}\frac{{\partial y}}{{\partial p}}\frac{{\partial p}}{{\partial u}} + \frac{{\partial w}}{{\partial z}}\frac{{\partial z}}{{\partial v}}\frac{{\partial v}}{{\partial u}} + \frac{{\partial w}}{{\partial z}}\frac{{\partial z}}{{\partial p}}\frac{{\partial p}}{{\partial u}}\]