1.已知实数x,y满足x=(根号y-3 )+(根号3-y)+2,求x的y次方的值.2.若根号x+根号-x有意义,则x
问题描述：
1.已知实数x,y满足x=(根号y-3 )+(根号3-y)+2,求x的y次方的值.2.若根号x+根号-x有意义,则x
1.已知实数x,y满足x=(根号y-3 )+(根号3-y)+2,求x的y次方的值.
2.若根号x+根号-x有意义,则x应满足（ ）.
3.已知|2008-a|+根号a-2009=a,求a-2008的值.
4.若实数x,y满足(根号x+2)+(y-根号3）的平方=0,则xy的值是（ ）.
答
1.y-3 >=0,3-y >=0,
y=3,x=2,
2^3 = 8
2.x>=0,-x>=0,x=0
3.a-2009>=0,a>=2009
a-2008 + 根号a-2009 =a
根号a-2009 = 2008
a-2009 = 2008^2
a = 4034073
4.x+2=0,x=-2
y=根号3
xy = -2*根号3