factorial method的用法和樣例：
例句
- By an analytic method, in this essay a vector invariant of a casual point to a tetrahedron on volume and deductions form vector invariant are given.
摘要利用解析法，給出空間任意一點與四面體體積有關的一個向量恆等式，並給出若干推論。 - At the airgap, magnetic field change is analysed through two-dimensional analytical method and two-dimensional finite-element method.
通過二維解析法和有限元法分析電動機不同氣隙時的氣隙磁場變化。
