In fact, it is to change the original formula into an exponential function with E as the base, and then only calculate the limit of the exponent.

For example, find the limit of (e a divided by e b):

The a power of e divided by the b power of e is equal to the a-b power of e, and then the limit of the original formula is equal to lim(a-b) of e, and that exp{} is a written language, that is, an exponential function based on e.