For the latter, since we transform the problem to seek to solve the secondorderdifferentialequation into that of twice integrations, the calculating process is also simple.
后者由于把一个二阶微分方程的求解转化成为两次积分问题，也使计算过程简化。
2
Based on the theory of differential geometry and geodesy, the secondorderdifferentialequation and the first differential relationship are derived on the regional earth ellipsoid in this paper.
The driveline for a tractor vehicle is simplified as a 2-DOFs(degree of freedom)torsional vibration system, and is described as a second-orderdifferentialequation.