Question

(k-1)(k-1)-4不等于0的充要条件是什么

Answer 1

(k-1)(k-1)-4≠0

即k-1≠±2,

即k≠3且k≠-1.

所以(k-1)(k-1)-4不等于0的充要条件是

k≠3且k≠-1.