Precisely rotational symmetry, such as x * x+y * y+z * z =1; X+y+z=sqrt(3), and sqrt(n) represents the root number n.

For the above equation, if X is replaced by Z, Y is replaced by X and Z is replaced by Y, and the form of the equation has not changed, it is said that X, Y and Z have rotational symmetry for the equation. If x * x+y * y+4 * z * z =1; If x+y+2*z=sqrt(3), x, y and z no longer have rotational symmetry.