Especially (lnx)' =1/x.

Logarithm and logarithmic function are important contents of high school mathematics, and they are required knowledge of college entrance examination, which needs students to master unconditionally. However, many students do not have a good grasp of logarithmic knowledge in senior one, which has become a stumbling block to mathematics learning in the whole senior high school.

Most students didn't learn logarithmic knowledge well, mainly because they thought there were too many logarithmic formulas and there was no order. It should be pointed out that:

Law of addition (subtraction): [f(x)+g(x)]'=f(x)'+g(x)'

Multiplication rule: [f (x) * g (x)]' = f (x)' * g (x)+g (x)' * f (x)

Division rule: [f (x)/g (x)]' = [f (x)' * g (x)-g (x)' * f (x)]/g (x) 2

Logarithmic attention of logarithmic function

Logarithm was originally produced to solve the calculation problems in astronomy. Because of its strong practical application, it has a wider range of applications. Especially in natural science, the application of natural logarithm to lnx is more common.

Logarithmic problems abound in the college entrance examination, especially in the finale of function and derivative, natural logarithmic function f(x)=lnx and compound function often appear. So logarithmic function is the most important function review.