method of limits

例句：

1. 1. The method of limits is used to solve problems that have infinite solutions.
   极限方法是解决具有无限解的问题的方法。
2. 2.In the method of limits, we can use a variable to represent a change in value.
   在极限方法中，我们可以使用一个变量来表示值的变化。
3. 3. The method of limits is often used in calculus to find the derivative of a function.
   极限方法通常用于微积分中，以找到函数的导数。