tìm tất cả các cặp số nguyên sao cho
#1
Đã gửi 14-10-2011 - 17:31
#2
Đã gửi 14-10-2011 - 20:19
Với $y<-3$ thì $(y-1)^3<y^3 + 2y^2 + 1<y^3$
Như vậy chỉ có $y \in \{-3,-2,1,0 \}$. Ta tìm được nghiệm $(x, y) \in \{(-2, -3), (1, -2),(1,0) \}$.
- perfectstrong yêu thích
Discovery is a child’s privilege. I mean the small child, the child who is not afraid to be wrong, to look silly, to not be serious, and to act differently from everyone else. He is also not afraid that the things he is interested in are in bad taste or turn out to be different from his expectations, from what they should be, or rather he is not afraid of what they actually are. He ignores the silent and flawless consensus that is part of the air we breathe – the consensus of all the people who are, or are reputed to be, reasonable.
Grothendieck, Récoltes et Semailles (“Crops and Seeds”).
#3
Đã gửi 14-10-2011 - 20:24
I'll always smile.
Try my best.
#4
Đã gửi 14-10-2011 - 20:52
Không phải đâu bạn, đề thi HSG Đồng Tháp là đề khác.bài này là đề thi hsg tỉnh Đồng Tháp do xusinst pót đã được Didier giải rồi đó.
Discovery is a child’s privilege. I mean the small child, the child who is not afraid to be wrong, to look silly, to not be serious, and to act differently from everyone else. He is also not afraid that the things he is interested in are in bad taste or turn out to be different from his expectations, from what they should be, or rather he is not afraid of what they actually are. He ignores the silent and flawless consensus that is part of the air we breathe – the consensus of all the people who are, or are reputed to be, reasonable.
Grothendieck, Récoltes et Semailles (“Crops and Seeds”).
#5
Đã gửi 15-10-2011 - 17:13
Không phải đâu bạn, đề thi HSG Đồng Tháp là đề khác.
sao phải xét y>0 va y<3 vả lại sao => y {-3, -2, 1, 0} hả bạn
nói chung mình không hiểu
bạn giải chi tiết cho mình với
- zookiiiiaa yêu thích
#6
Đã gửi 15-10-2011 - 17:19
Xét như vậy để tìm giới hạn mà pt ko tìm được nghiệm.
Với $y>0$ thì $y^3<y^3 + 2y^2 + 1<(y+1)^3$
Với $y<-3$ thì $(y-1)^3<y^3 + 2y^2 + 1<y^3$
Như vậy chỉ có $y \in \{-3,-2,1,0 \}$. Ta tìm được nghiệm $(x, y) \in \{(-2, -3), (1, -2),(1,0) \}$.
sao phải xét y>0 va y<3 vả lại sao => y {-3, -2, 1, 0} hả bạn
nói chung mình không hiểu
bạn giải chi tiết cho mình với
Discovery is a child’s privilege. I mean the small child, the child who is not afraid to be wrong, to look silly, to not be serious, and to act differently from everyone else. He is also not afraid that the things he is interested in are in bad taste or turn out to be different from his expectations, from what they should be, or rather he is not afraid of what they actually are. He ignores the silent and flawless consensus that is part of the air we breathe – the consensus of all the people who are, or are reputed to be, reasonable.
Grothendieck, Récoltes et Semailles (“Crops and Seeds”).
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