1、lim(f(x)+g(x))=limf(x)+limg(x).

2、lim(f(x)-g(x))=limf(x)-limg(x).

3、lim(f(x)*g(x))=limf(x)*limg(x)。

Lim limit operation formula abstract, p> limit law of difference and product. Only when the limits of numerator and denominator exist, and the limit of denominator is not zero, can the limit law of quotient be used. When a limit itself does not exist, none of the four algorithms can be used.

Four algorithms of limit Only when two limits exist at the same time can the four limits of limit be converted by four limits.

Special usage of limit four operations

Because in the exam, we know that the limit can be solved in the end, so when we split them by the four limit operations, as long as the limit of one component obviously exists, we can judge that this splitting method is reasonable, and calculate the part with obvious limit first. The following is a clear mathematical formula:

Limf(x) = LIMF (G (X)+H (X)), if Limf(x) and LIMF (X) exist, LIMF (X) = LIMF (X)+limg(x).

This method gives people the feeling of partial substitution and gradually becomes an important means to simplify the limit.