Question

[Nguyễn Mary]

tìm GTNN của:

E=2x²+2xy+5y²-8x-22y

Answer 1

[Linh Lê]

2.x2+2.x(y−4)+5.y2−22y2.(x+y+42)2+10y2−44y−(y+4)222.(x+y+42)2+9y2−52y−1622.(x+y+42)2+9(y−269)2−820922.(x+y+42)2+92.(y−269)2−4109≥−4109⇒minA=−4109y=269x=−319