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duwc Cviai binvC
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ding lhfrc Iran
bién ru hién khéng‘? Cu hoi nély sé du'Q'c tra
k€1
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suu khi chimg ta
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xcm xét bi lozin sau dy:
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hé $6 ducmg nén:
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véi bit ding thtrc Iran 1996.
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hm hém g(c) ta c6: g'(c) =-
Nhin vo biéu
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aéng thirc hai bién $6. va ky thuét bién aéa trén da gilip chng ta
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chi: y rang, mm bévcléng thtrc 06 diéu kién ba bié_n $6 cng
dung mét caich triét dé nht diéu kién khi du'a_b§t déng thirc vé hai bién. Til"
chng ta c6
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lil
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ding thtrc hai bién
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