variational formula

例句：

1. 1. The variational formula is used to solve optimization problems.
   变分公式用于解决优化问题。
2. 2. In the variational formula, the minimization of the objective function is equivalent to the maximization of the Lagrangian.
   在变分公式中，最小化目标函数等价于拉格朗日乘子的最大化。
3. 3. The variational formula can be used to find the minimum point of a function in a multi-dimensional space.
   变分公式可用于在多维空间中找到函数的最小点。