Question

\(\frac{x^2}{x^2-5x+7}\) tim gtnn va gtln

 

Answer 1

\(S=\sqrt{x-1}+\sqrt{2x^2-5x+7}\)

\(\Rightarrow S^2=2x^2-4x+6+2\sqrt{x-1.2x^2-5x+7}\)

\(=2.x-1^2+4+2\sqrt{x-1.2x^2+5x-7}\ge4\)

\(Min_A=4\Leftrightarrow x=1\)

Vậy: \(x=1\)

P/s: Đúng ko nhỉ?

Answer 2

bạn ơ\(\sqrt{x-1}+\sqrt{2x^2-5x+7}\)i  sao ra cai do vay