15.设实数满足约束条件,则的取值范围是_____________.
设实数x,y满足约束条件如图,记k=(y+1)/(x-2),则k的取值范围为?
设实数x,y满足x2+y2=1则 xy的取值范围是?
设x、y满足约束条件{x≥0 y≥x 4x+3y≤12}则2y+3/x+1的取值范围是?
设变量x,y满足约束条件 x+y≤a x+y≥8 x≥6且不等式x+2y≤4恒成立,则实数a的取值范围
设实数x,y满足约束条件x≥1且x≠2y≥1x+2y−5≤0,则z=x+y−1x−2的取值范围为( )
若实数x y满足约束条件x≤2 y ≤2 x+y≥2 则x+2y的取值范围
设实数xy满足x2 +2y2=6,则x+y的取值范围
(2014•新余二模)设实数x,y满足约束条件x−y−2≤0x+2y−5≥0y≤2,则u=2x+yx+2y的取值范围是(
已知x、y是实数且满足x2+xy+y2-2=0,设M=x2-xy+y2,则M的取值范围是______.
若实数变量x,y满足约束条件x+2y>=2,2x-y=-1,则目标函数k=y+1/x+1的取值范围是
(2008•杭州一模)设实数x,y满足x2+2xy-1=0,则x+y的取值范围是______.
设实数x,y满足x2+2xy-1=0,则x+y的取值范围是______.