Toán nâng cao

T

transformers123

Ta có:

$2x+xy = 4$

$\iff 2\sqrt{2x^2y} \le 4$ (bđt Cauchy)

$\iff \sqrt{2A} \le 2$

$\iff 2A \le 4$

$\iff A \le 2$

Dấu "=" xảy ra khi $2x=xy$
 
You must log in or register to reply here.
Top Bottom