$$\text{黑森西}{H}_{\mathrm{一世}j}=\frac{{\partial }^{2}F}{\partial X_{\mathrm{一世}}\partial X_j}。$$

$$\mathrm{L.}=F+{\displaystyle \underset{\mathrm{一世}}{\sigma .}{\mathrm{\lambda .}}_{\mathrm{一世}}{C}_{\mathrm{一世}}}+{\displaystyle \underset{j}{\sigma .}{\mathrm{\lambda .}}_{j}C\mathrm{E.}{\mathrm{问：}}_j}。$$

$$H={\nabla }^2\mathrm{L.}={\nabla }^{2}F+{\displaystyle \underset{\mathrm{一世}}{\sigma .}{\mathrm{\lambda .}}_{\mathrm{一世}}{\nabla }^2{C}_{\mathrm{一世}}}+{\displaystyle \underset{j}{\sigma .}{\mathrm{\lambda .}}_j{\nabla }^{2}C\mathrm{E.}{\mathrm{问：}}_j}。$$