$\displaystyle \left(a+\dfrac{1}{b}\right).\left(b+\dfrac{1}{c}\right).\left(c+\dfrac{1}{a}\right)\geq \left(\dfrac{10}{3}\right)^3$
$(2)\;\; a,b,c\in \left[0,\infty\right)$. Then prove that
$\displaystyle \left(a-\dfrac{1}{b}\right). \left(b-\dfrac{1}{c}\right). \left(c-\dfrac{1}{a}\right)\geq \left(a-\dfrac{1}{a}\right). \left(b-\dfrac{1}{b}\right). \left(c-\dfrac{1}{c}\right)$
Bài viết đã được chỉnh sửa nội dung bởi stuart clark: 15-10-2011 - 10:57