Question

Tìm GTLN của:

A=\(\frac{1}{5x+3\sqrt{x}+8}\)

Answer 1

ĐKXĐ : \(x\ge0\)

\(A=\frac{1}{5x+3\sqrt{x}+8}\le\frac{1}{5.0+3\sqrt{0}+8}=\frac{1}{8}\)

Dấu "=" xảy ra <=> x = 0

Vậy ...

Answer 2

ĐK: x > 0 

Vì x > 0

nên \(5x+3\sqrt{x}+8\ge0+0+8=0\)

\(\Rightarrow\frac{1}{5x+3\sqrt{x}+8}\le\frac{1}{8}\)

Dấu "='' <=> x = 0