differential equation of higher order

例句：

1. 1. The differential equation of the motion of a particle is given by F = ma, where F is the force, m is the mass, and a is the acceleration.
   一个粒子的运动微分方程由F = ma给出，其中F是力，m是质量，a是加速度。
2. 2. In higher-order partial differential equations, the derivatives are taken with respect to variables that vary over time or space.
   在更高阶的偏微分方程中，导数是相对于随时间或空间变化的变量进行的。
3. 3. The differential equation of the motion of a particle in a gravitational field is given by F= mg - m(g - a)sinθ, where F is the force, g is the acceleration due to gravity, m is the mass, a is the acceleration due to gravity, and θ is the angle between the direction of the force and the vertical.
   在引力场中，一个粒子的运动微分方程为F = mg - m(g - a)sinθ，其中F是力，g是因重力而产生的加速度，m是质量，a是因重力而产生的加速度，θ是力与垂直方向之间的角度。