Đăng bài 03-05-12 03:33 PM
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Đăng bài 02-05-12 09:53 AM
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Đăng bài 27-04-12 04:43 PM
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Giải và biện luận hệ phương trình sau tùy theo tham số $m$ :
$\left\{ \begin{array}{l}
{\log _{\frac{1}{{\sqrt 2 }}}}\left( {\frac{{1 - 5co{s^4}3x}}{2}} \right) \le 2\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\
\frac{{1 + \sin \,x}}{{\sin \,2x}} \le m\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2)
\end{array} \right.$
Đăng bài 27-04-12 08:21 AM
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Giải các hệ :
$1)\,\,\,\left\{ \begin{array}{l}
{2^x} + {2^y} \le 1\\
x + y \ge - 2
\end{array} \right.\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2)\,\,\,\left\{ \begin{array}{l}
{4^{x + y - 1}} + {3.4^{2y - 1}} \le 2\\
x + 3y \ge 2 - {\log _4}3
\end{array} \right.$
Đăng bài 26-04-12 04:59 PM
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Giải các hệ :
$\begin{array}{l}
1)\,\,\,\left\{ \begin{array}{l}
{\log _x}\left( {x + 2} \right) > 2\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\
{\log _2}{2^{x - 1}} + {\log _2}\left( {{2^{x + 1}} + 1} \right) < {\log _2}\left( {{{7.2}^x} + 12} \right)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2)
\end{array} \right.\\
2)\,\,\,\left\{ \begin{array}{l}
{\log _{7 - x}}\left( {y - 4} \right) < 0\\
{\log _{y - 1}}\left( {3 - x} \right) < 0
\end{array} \right.
\end{array}$
Đăng bài 26-04-12 04:53 PM
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Giải hệ:
$\left\{ \begin{array}{l}
{2^{\left| {{x^2} - 2x - 3} \right| - {{\log }_2}3}} = {3^{ - y - 4}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\
4\left| y \right| - \left| {y - 1} \right| + {\left( {y + 3} \right)^2} \le 8\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2)
\end{array} \right.$
Đăng bài 26-04-12 04:50 PM
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Giải hệ :
$\left\{ \begin{array}{l}
\log _2^2x - {\log _2}{x^2} < 0\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\
\frac{{{x^3}}}{3} - 3{x^2} + 5x + 9 > 0\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2)
\end{array} \right.$
Đăng bài 26-04-12 04:48 PM
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Đăng bài 25-04-12 04:32 PM
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Đăng bài 24-04-12 03:55 PM
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