wikipedia1995
New member
- Xu
- 0
e có cách khác anh sỹ
\[VT\ge \frac{(\sum_{cyc}a^2)^2}{\sum_{cyc}(a+b)(a^2+b^2)}\ge \frac{(\sum_{cyc}a^2)^2}{6\sum_{cyc}a^3}\]
\[<=>4(\sum_{cyc}a^2)^2\ge 6(a+b+c)(a^3+b^3+c^3)\]Done!!!!!
\[VT\ge \frac{(\sum_{cyc}a^2)^2}{\sum_{cyc}(a+b)(a^2+b^2)}\ge \frac{(\sum_{cyc}a^2)^2}{6\sum_{cyc}a^3}\]
\[<=>4(\sum_{cyc}a^2)^2\ge 6(a+b+c)(a^3+b^3+c^3)\]Done!!!!!