Since kindergarten, we have learned all the way, and we are constantly deepening our understanding of numbers. The expansion of the number system roughly has the following stages: 1. The natural number generated for counting needs, that is, the set of positive integers.

Starting from kindergarten, we have learned along the way, and we are constantly deepening our understanding of numbers. The expansion of the number system is roughly the following stages:

1. The natural number generated for the counting requirement, that is, the positive integer set

2. The "0" introduced by supplementing the counting requirement, that is, the natural number set

3. The subtraction operation produces negative integers, and the whole integer is the integer set

4. The division operation produces fractions, and the integer and fraction are combined into rational number set

5. The square operation produces irrational number . The rational number and irrational number are combined into the real number set

6. The negative number square operation produces imaginary number . The real number and imaginary number are combined into the complex number set

0. The complex number can not only perform square operation, but also logarithmic and trigonometric function can be implemented in the complex number set. Let’s take a closer look at this mysterious collection through 9 questions and relying on the knowledge points in high school just by looking at the knowledge points in high school.

Question 1. Definition of imaginary numbers

Question 2. Application of Euler formulas

Question 3. Extension of logarithm a

Question 4. Extension of logarithm b

Question 0 Question 0 Question 0 5. Logarithm extension c

question 6. Expansion of exponent

question 7. Expansion of triangle a

question 8. Expansion of triangle b

question 9. Expansion of trigonometric function c