1.
Let z1=2+3iz_1 = 2 + 3i and z2=3+4iz_2 = 3 + 4i. The set
S={zC:zz12zz22=z1z22}S = \left\{z \in \mathbb{C} : |z - z_1|^2 - |z - z_2|^2 = |z_1 - z_2|^2\right\}

represents a: