δx=limδx→0(uδvδx+vδuδx+δuδvδx)=ulimδx→0δvδx+vlimδx→0δuδx+limδx→0δuδvδx{\displaystyle {\begin{aligned}{\frac {\delta y}{\delta x}}&=u{\frac {\delta v}{\delta x}}+v{\frac {\delta u}{\delta x}}+{\frac {\delta u\delta v}{\delta x}}\\\lim \limits _{\delta x\to 0}{\frac {\delta y}{\delta x}}&=\lim \limits _{\delta x\to 0}\left(u{\frac {\delta v}{\delta x}}+v{\frac {\delta u}{\delta x}}+{\frac {\delta u\delta v}{\delta x}}\right)\\&=u\lim \limits _{\delta x\to 0}{\frac {\delta v}{\delta x}}+v\lim \limits _{\delta x\to 0}{\frac {\delta u}{\delta x}}+\lim \limits _{\delta x\to 0}{\frac {\delta u\delta v}{\delta x}}\\\end{aligned}}}එමනිසා dydx{\displaystyle {\frac {dy}{dx}}} අර්ථ දැක්වීම අනූවdydx=udvdx+vdudx+0{\displaystyle {\frac {dy}{dx}}=u{\frac {dv}{dx}}+v{\frac {du}{dx}}+