用等价无穷小代换求极限

Find the limit by substitution of equivalent infinitesimal

用等价无穷小代换求一般极限的方法需要讨论,求具有高阶导数的函数的等价无穷小还有些一般方法.

Some ways will be discussed in the thesis with which we can take advantage of the substitution of equivalent infinitesimal to seek an ordinary limit. On the other hand,a general method also be offered with which we can seek the equivalent infinitesimal of function with derivatives of higher orders.