Đáp án:
`M_(max)=12 <=> x=3`
Giải thích các bước giải:
`M=6x-x^2+3`
`=-(x^2-6x-3)`
`=-[(x^2-2.x.3+3^2)-3^2-3]`
`=-[(x-3)^2-12]`
`=-(x-3)^2+12<=12`
Dấu "=" xảy ra `<=> x-3=0`
`=> x=3`
Vậy `M_(max)=12 <=> x=3`
$M =6x -x^2 +3$
$=-(x^2 -6x -3)$
$=-(x^2 -2.x.3 +9-12)$
$=-(x-3)^2+12$
Vì $-(x-3)^2 ≤ 0$
Nên $-(x-3)^2 +12 ≤ 12$
Dấu ''='' xảy ra khi $x-3=0 ⇔ x=3$
Vậy Max M $=12$ tại $x=3$
Giúp vs thắc mắc quá:|4x-17|=x^2-4x-5.Tìm x nhé
Trả lời giúp mik câu 1,2,3,4 nha Thks
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Hãy tưởng tượng và kể lại cuộc đọ sức của Sơn Tinh và Thủy Tinh trong thời kì hiện đại (Viết 1 bài văn để tả cuộc đọ sức nha)
2. After I had had my dinner, I invited Linda for a walk. A. Tinvited Linda for a walk. Then, we had dinner. B. Before I had my dinner, I had invited Linda for a walk. C. Having had my dinner, I invited Linda for a walk. . Alter she had spent the whole month studving the effects of deforestation, she Is party, we bought some flowers. collected enough data. A. She had collected enough data but she still spent the whole month studying the effects of deforestation. B. Having spent the whole month studying the effects of deforestation, she collected enough data. C. After she collected enough data, she spent the whole month studying the effects of deforestation. 4. He risked his own life to rescue a girl from drowning. He was really admired for that. A. He was really admired for having risked his own life to rescue a girl from drowning. B. Because he was really admirable, he risked his own life to rescue a girl from drowning. C. He had been really admired before he risked his own life to rescue a girl from drowning. 5. Since the local authorities had failed to manage water resources efficiently, they had to deal with water shortages. A. The local authorities had to deal with water management and water shortage at the same time. B. Having had to deal with water shortages, the local authorities failed to manage water resources efficiently. C. Having failed to manage water resources efficiently, the local authorities had to deal with water shortages. 6. Tom broke his promise to keep my secret. He apologised for that. A. Having broken his promise to keep my secret, he apologises for that. B. Tom apologised to me for having broken his promise to keep my secret. C. When Tom breaks his promise to keep my secret, he apologises for that. 7. Lan has come up with creative solutions for dealing with air pollution. We praise her for that.
Các đới khí hậu cực và cận cực, đới khí hậu xích đạo ở châu Á lại không phân hóa thành các kiểu khí hậu khác nhau là do?
S=1+2+3+...+2007 S=21+23+25+...+1001 S=2+4+6+...+998+1000 S=1+2+2^2+2^3+...+2^200
Em có nhận xét gì về tình hình nước Nhật Bản trong những năm 1918-1929
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