→ kin925 :我有想過,不過我的想法是a+b<-2,ab>1,結果算不出 02/10 23:47
→ kin925 :答案給的那樣,不知道問題出再哪 02/10 23:48
→ theoculus :滿足 a+b<-2,ab>1 並不保證 a>-1且b>-1 02/11 00:02
→ theoculus :ex: a = -3 ; b=-2 02/11 00:02
→ theoculus :要像本文的條件那樣才可以 02/11 00:03
→ theoculus :由 (i)(a+1)(b+1)>0 可知 a,b需同時大於-1 or小於-1 02/11 00:04
→ theoculus :再由2可知 兩個都必須 小於 -1 02/11 00:04
→ theoculus :...我第一行後面打錯了 不保證 a<-1且b<-1 02/11 00:05
→ theoculus :ex : a = -0.5 ; b = -4 02/11 00:06