I is the unit of imaginary number, which is exactly the unit length of imaginary axis. Aren't I and J used to represent the unit vectors of X and Y on the coordinate axis?

I was put forward to solve an equation without a real number solution. It is stipulated that the root of-1 is plus or minus i.

The first power, the second power and the third power of I are equal to I,-1,-i.

Just as 1 is the basic unit of an imaginary number, so is 2 = 2 * 1 and 2i = 2 * i.

The imaginary number in denominator is to multiply the numerator and denominator by a yoke imaginary number at the same time, that is, the imaginary number with the same real part and the opposite imaginary part.

So after multiplying (1+i), the denominator is (1+i) (1-I) =1-i * i = 2, so the result is (1-i), plus z, and finally you.