Cho $x,y > 0$ và $x+ y + 2xy = 12$
Tìm $\min A= x+ y$
Edited by perfectstrong, 29-05-2021 - 15:02.
Tiêu đề + LaTeX
$\min A= x+ y$ biết $x+ y + 2xy = 12$
Started By chiellyhuyen123, 29-05-2021 - 05:46
#1
Posted 29-05-2021 - 05:46
chiellyhuyen123
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#2
Posted 30-05-2021 - 08:28
DBS
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Ta có: $24=2(x+y)+4xy\leqslant 2(x+y)+(x+y)^2\Rightarrow (x+y)^2+2(x+y)-24\geqslant0\Rightarrow x+y\geqslant 4$
Vậy $A_{Min}=4$
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