已知x2+y2-4x-6y+12=0,则x+2y的取值范围是
已知实数x,y满足x2+y2-4x+1=0,求2x+y的取值范围?
已知函数x,y满足x2+y2=2x,则x2+y2的取值范围
已知点p(x,y)是圆x2+y2-2y-3=0上任意一点则X2+(y+2)2的取值范围
已知实数x,y满足x2+y2=4,求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满足x2+y2=2x,则x2y2的取值范围是______.
已知实数x.y满足x2+y2=4.则3x+4y的取值范围是
已知实数x,y满足x2+ y2=6x,则z=x2+y2+2x的取值范围
已知P(x,y)是圆(x-1)2+(y+1)2=4上一动点,则x2+y2的取值范围-----------
x、y是自然数,x2+2xy+4y2=6,则x2+4y2的取值范围是 ( ) 请教详细解答过程,
已知x,y满足x2/9+y2/4=1,则xy的取值范围是?