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The set of complex numbers is the sum of a real number and an imaginary number in the form:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807211044971-1943455315.png)
It can be considered that all real numbers are complex numbers with b=0 and all imaginary numbers are complex numbers with a=0.
addition:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807211353924-1702165693.png)
Subtraction:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807211518237-1474500979.png)
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807211544987-245287376.png)
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807211749893-23057925.png)
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807212039518-407255343.png)
Conjugation of a complex number means making the imaginary part of a complex number negative. The symbol for conjugate complex numbers is .
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807212241362-134544887.png)
The product of a complex number and its complex conjugate is:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807212445143-1619345177.png)
We use complex conjugates to compute the absolute value of complex numbers:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807212536580-1468370005.png)
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807212602455-1162386492.png)
If the square of is equal to -1, then
the nth power should also exist:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807212841221-215564354.png)
If you write in this order, you will get a pattern like this: (1,\mathbf i,-1,-\mathbf i,1,...)
A similar pattern also occurs with increasing negative powers:
![](https://images2017.cnblogs.com/blog/1196054/201708/1196054-20170807213027705-1676310991.png)