已知实数XY 满足X2+Y2=1,求Y+2/X+1的取值范围

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? 设实数x,y满足x2+y2=1则 xy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 设实数xy满足x2 +2y2=6,则x+y的取值范围 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______． 已知实数x,y满足(x2)+(y2)-xy+2x-y+1=0,求x,y的值 已知实数x、y满足X2+y2-xy+2x-y+1=0,试求x、y的值 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 已知实数x,y,z满足以下条件,求x的取值范围.x+y+z=a,x2+y2+z2=1/2 a2