若实数x,y满足x2+y2=4则2xy/x+y-2的取值范围为____
设实数xy满足x2 +2y2=6,则x+y的取值范围
设实数x,y满足x2+y2=1则 xy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______.
实数x、y满足x2+xy+y2=2,记u=x2-xy+y2,则u的取值范围是
已知实数xy满足x2+y2=4.则y+3/x+1的取值范围为
已知实数XY 满足X2+Y2=1,求Y+2/X+1的取值范围
已知实数x,y满足x2+y2-4x+1=0,求2x+y的取值范围?
若实数XY满足X2+Y2=1,则X-2Y的最大值为
若实数x,y,z满足x+2y+3z=a( a为常数 ),则x2 + y2 + z2的取值范围是
已知实数x,y满足x2+y2=4,求x+y的取值范围
已知实数x,y满足x2+2xy+3y2-8y+6=0,求x,y的取值范围
已知实数xy满足x2+y2-4x+3=0则(x+y-3)/(x-y+1)的取值范围是