已知实数x,y满足条件{2x-y+1≥0,2x+y≥0,x≤1,求z=x+3y的最小值.

问题描述:

已知实数x,y满足条件{2x-y+1≥0,2x+y≥0,x≤1,求z=x+3y的最小值.

先画出直线2x-y+1=0和直线2x+y=0和x=1先确定可行域将(0,0)分别代入,则入,且满足2x-y+1≥0,x≤1即(0,0)在可行域内再画出x+3y=0显然x=1,2x+y=0交点处取最小值x=1     2x+y=0联立  y=-2所以z=...