Mì-fûn-ho̍k

Mì-fûn-ho̍k.

Mì-fûn-ho̍k (Differential of a function) he thûng-ko thô-sú lâu mì-fûn lòi ngièn-kiu Khiuk-sien Chhià-sut, Kâ-suk-thu, Chui-thai Chhṳ̍t lâu Chui-séu Chhṳ̍t ke yit-mùn ho̍k-khô. Mì-fûn-ho̍k ke chok-yung chhai yî mèu-shu̍t lióng-ke pien-sú chṳ̂-kiên ke pien-fa kôan-he, thûng-sòng yung lióng-ke pien-sú ke mì-fûn sông ke hâm-sú lòi mèu-shu̍t yit-ke hâm-sú ke pien-fa tshi-sṳ, ya chhṳ̂n-vì "mì song" fe̍t "khiù-thô", thûng-sòng ki-chok ${\begin{smallmatrix}{\frac {\mathrm {d} y}{\mathrm {d} x}}\end{smallmatrix}}$.

Chú-yeu khói-ngiam

$dy=f'(x)\,dx,$

$dy={\frac {dy}{dx}}\,dx$

$df(x)=f'(x)\,dx.$