1.x*** yoke +y*** yoke =(x+y)*** yoke.

Because (x +y) * * yoke, its real part is x real part+y real part, and its imaginary part is x*** yoke imaginary part +Y * * yoke imaginary part.

2.x*x*** Yoke = | X | 2

Because let x=a+bi, then x*** yoke =a-bi is obtained by (a+bi) (a-bi) = a 2+b 2 = | x | 2.

Therefore, these three steps are established. |z+ 1|^2

= 1, which can be understood as the square of the distance from Z to (-1, 0) is 1, that is, the distance from Z to it is 1, so the trajectory is centered at (-1, 0) and the radius is 1