349 reputation
29
bio website
location
age
visits member for 1 year, 11 months
seen Apr 6 '13 at 7:34

Jul
2
awarded  Curious
Oct
4
awarded  Yearling
Apr
4
revised Prove $ |\vec{a_1}-\vec{b}|+ \cdots +|\vec{a_n}-\vec{b}| > n $
added 1 characters in body; edited title
Apr
4
comment Prove $ |\vec{a_1}-\vec{b}|+ \cdots +|\vec{a_n}-\vec{b}| > n $
I try $|\overrightarrow{{{a}_{1}}}-\vec{b}|+\cdots +|\overrightarrow{{{a}_{n}}}-\vec{b}|\ge |\overrightarrow{{{a}_{1}}}+\cdots +\overrightarrow{{{a}_{n}}}-n\vec{b}|=|n\vec{b}|>n$,but I use $|\overrightarrow{b}|>1$,not use $|\vec{a_i}|>1$,
Apr
4
asked Prove $ |\vec{a_1}-\vec{b}|+ \cdots +|\vec{a_n}-\vec{b}| > n $
Mar
28
asked If $x^9-x^5+x-2=0$ , how to prove $\sqrt[11]{3}<x<\sqrt[10]{3}$ ,$\sqrt[7]{2}<x<\sqrt[6]{2}$.
Mar
26
accepted How to prove ${{a}^{a}}{{b}^{b}}\ge {{\left(\frac{a+b}{2}\right)}^{a+b}}$ ?thanks.
Mar
26
awarded  Commentator
Mar
26
comment How to prove ${{a}^{a}}{{b}^{b}}\ge {{\left(\frac{a+b}{2}\right)}^{a+b}}$ ?thanks.
$a>0$,$b>0$, thanks.
Mar
26
revised How to prove ${{a}^{a}}{{b}^{b}}\ge {{\left(\frac{a+b}{2}\right)}^{a+b}}$ ?thanks.
added 14 characters in body
Mar
26
asked How to prove ${{a}^{a}}{{b}^{b}}\ge {{\left(\frac{a+b}{2}\right)}^{a+b}}$ ?thanks.
Mar
21
accepted how to prove $\frac{a}{1+b+c}+\frac{b}{1+c+a}+\frac{c}{1+a+b}+(1-a)(1-b)(1-c)\le 1$
Mar
21
comment how to prove $\frac{a}{1+b+c}+\frac{b}{1+c+a}+\frac{c}{1+a+b}+(1-a)(1-b)(1-c)\le 1$
thank you very much
Mar
20
asked how to prove $\frac{a}{1+b+c}+\frac{b}{1+c+a}+\frac{c}{1+a+b}+(1-a)(1-b)(1-c)\le 1$
Mar
8
asked If $\sqrt{3}x-y<0$ , $x-\sqrt{3}y+2<0$ , $y\ge 0$, are known, how to calculate the range of $\frac{\sqrt{3}x+y}{\sqrt{{{x}^{2}}+{{y}^{2}}}}$.
Mar
6
accepted prove $ \frac{1}{13}<\frac{1}{2}\cdot \frac{3}{4}\cdot \frac{5}{6}\cdot \cdots \cdot \frac{99}{100}<\frac{1}{12} $
Mar
6
awarded  Nice Question
Mar
6
asked prove $ \frac{1}{13}<\frac{1}{2}\cdot \frac{3}{4}\cdot \frac{5}{6}\cdot \cdots \cdot \frac{99}{100}<\frac{1}{12} $
Mar
2
accepted Calculate $1\times 3\times 5\times \cdots \times 2013$ last three digits.
Mar
2
asked Calculate $1\times 3\times 5\times \cdots \times 2013$ last three digits.