Question

設(shè)=(1,),=(0,1),O為坐標(biāo)原點(diǎn),動(dòng)點(diǎn)P(x,y)滿足0≤·≤1,0≤·≤1,則z=y-x的最大值是(　　)

(A) (B)1 (C)-1 (D)-2

 

Answer 1

A

【解析】依題意得畫出可行域,可知當(dāng)直線z=y-x經(jīng)過點(diǎn)(-,1)時(shí),z取得最大值,最大值為z=1-(-)=.