2. the third power of I is-I.

3. The fourth azimuth of I is 1.

The fifth power of I is i.

We call a number in the form of z = a+bi (a both a and b are real numbers) a complex number. When imaginary part b=0, complex number z is a real number;

When imaginary part b is not equal to 0, complex number z is imaginary; When the imaginary part B is not equal to 0 and the real part A is equal to 0, the complex number Z is purely imaginary.

In addition, the calculation formula is: i^2 =? 1。

Extended data

The addition rule of complex numbers: let z 1=a+bi and z2=c+di be any two complex numbers. The real part of sum is the sum of the original two complex real parts, and its imaginary part is the sum of the original two imaginary parts. The sum of two complex numbers or a complex number.

Multiplication rule

Complex multiplication rule: two complex numbers are multiplied, similar to two polynomials. In the result, i2=-1, and the real part and imaginary part are merged respectively. The product of two complex numbers is still a complex number.