英语语法分析

The net momentum is the vectorial sum of these two, which is this.

总动量为，两者的矢量和，也就是这个东西。

Therefore there is a total angular momentum which is the vectorial sum of the two.

因此，总的角动量,有两个向量。

Numerical and vectorial analysis Differential calculus: multivariable functions.

数值和矢量分析微分：多变量函数。