Chủ đề này có 34 trả lời

[kokothoat]

$\frac{a}{b}$

[trthientuong]

2\frac{a}{b} = \frac{8}{4}\frac{a}{b}

[deuthatday]

*** Cannot compile formula:
\begin{document}$a^{2-a}_1+\dfrac{1}{a_1}$\begin{itemize}\item $a+1=b$\item $b+1=1$\end{itemize}Ket thuc\end{document}

*** Error message:
Error: Nothing to show, formula is empty

[deuthatday]

*** Cannot compile formula:
\begin{tikzpicture}\coordinate (A) at (0,0);\coordinate (B) at (-60:12cm);\coordinate (C) at (240:12cm);\foreach \density in {20,30,...,160}{%\draw[fill=MidnightBlue!\density] (A)--(B)--(C)--cycle;\path(A) coordinate (X)-- (B) coordinate[pos=.15](A)-- (C) coordinate[pos=.15](B)-- (X) coordinate[pos=.15](C);}\end{tikzpicture}

*** Error message:
Error: Nothing to show, formula is empty

[deuthatday]

*** Cannot compile formula:


\begin{tikzpicture}[scale=2]
\shade[top color=blue,bottom color=gray!50]
(0,0) parabola (1.5,2.25) |- (0,0);
\draw (1.05cm,2pt) node[above]
{$\displaystyle\int_0^{3/2} \!\!x^2\mathrm{d}x$};

\draw[style=help lines] (0,0) grid (3.9,3.9)
[step=0.25cm] (1,2) grid +(1,1);

\draw[->] (-0.2,0) -- (4,0) node[right] {$x$};
\draw[->] (0,-0.2) -- (0,4) node[above] {$f(x)$};

\foreach \x/\xtext in {1/1, 1.5/1\frac{1}{2}, 2/2, 3/3}
\draw[shift={(\x,0)}] (0pt,2pt) -- (0pt,-2pt) node[below] {$\xtext$};

\foreach \y/\ytext in {1/1, 2/2, 2.25/2\frac{1}{4}, 3/3}
\draw[shift={(0,\y)}] (2pt,0pt) -- (-2pt,0pt) node[left] {$\ytext$};

\draw (-.5,.25) parabola bend (0,0) (2,4) node[below right] {$x^2$};
\end{tikzpicture}


*** Error message:
Error: Nothing to show, formula is empty

[deuthatday]

*** Cannot compile formula:


$a^{2-a}_1+\dfrac{1}{a_1}$
\begin{itemize}
\item $a+1=b$
\item $b+1=1$
\end{itemize}
Ket thuc \\
\begin{tikzpicture}[scale=2]
\shade[top color=blue,bottom color=gray!50]
(0,0) parabola (1.5,2.25) |- (0,0);
\draw (1.05cm,2pt) node[above]
{$\displaystyle\int_0^{3/2} \!\!x^2\mathrm{d}x$};

\draw[style=help lines] (0,0) grid (3.9,3.9)
[step=0.25cm] (1,2) grid +(1,1);

\draw[->] (-0.2,0) -- (4,0) node[right] {$x$};
\draw[->] (0,-0.2) -- (0,4) node[above] {$f(x)$};

\foreach \x/\xtext in {1/1, 1.5/1\frac{1}{2}, 2/2, 3/3}
\draw[shift={(\x,0)}] (0pt,2pt) -- (0pt,-2pt) node[below] {$\xtext$};

\foreach \y/\ytext in {1/1, 2/2, 2.25/2\frac{1}{4}, 3/3}
\draw[shift={(0,\y)}] (2pt,0pt) -- (-2pt,0pt) node[left] {$\ytext$};

\draw (-.5,.25) parabola bend (0,0) (2,4) node[below right] {$x^2$};
\end{tikzpicture}


*** Error message:
Error: Nothing to show, formula is empty

Bài viết đã được chỉnh sửa nội dung bởi deuthatday: 13-06-2017 - 21:52

[deuthatday]

*** Cannot compile formula:
$a^{2-a}_1+\dfrac{1}{a_1}$\begin{itemize}\item $a+1=b$\item $b+1=1$\end{itemize}Ket thuc

*** Error message:
Error: Nothing to show, formula is empty

Bài viết đã được chỉnh sửa nội dung bởi deuthatday: 13-06-2017 - 21:54

[deuthatday]

Bài 1: Cho $a, b, c$ là các số thực dương thỏa mãn \({a^2} + {b^2} + {c^2} + abc = 4\). Chứng minh rằng: \(a + b + c \ge 3\).

Bài 2: Chứng minh rằng nếu $x,y,z$ là các số thực dương thảo mãn điều kiện:

\[\left\{ \begin{array}{l} x + y + z > 0\\ xy + yz + zx > 0\\ xyz > 0 \end{array} \right.\]

Chứng minh rằng $x>0$

Bài viết đã được chỉnh sửa nội dung bởi deuthatday: 13-06-2017 - 22:02

[deuthatday]

\[\left\{ \begin{array}{l} x + y + z > 0\\ xy + yz + zx > 0\\ xyz > 0 \end{array} \right.\]

[thuyvan1990]

ax + by+c = 0

[DaoLeAnhThu123]

$\frac{a}{b}+1$

[Lost The Ring]

$ frac{x}{y+z}$

[Lost The Ring]

$ frac{1}{a+b}$

[vietlao001]

Thử: 

[vietlao001]

$B = \sqrt {11}  + \sqrt {12} $