Question

实数k取什么值时,复数z=k^2+k-6+(k^2-2k)i是： ①实数?②虚数?③纯虚数?

Answer 1

z=[(k+3)(k-2)]+k(k-2)i.【1】k=0,或k=2.【2】k≠0且k≠2.【3】k=-3.