题目真没错?y=√(1-x^2)+√(x^2-1)+3由定义域知:1-x^2≥0,x^2≤1x^2-1≥0,x^2≥1则x^2=1,x=±1当x=1时,y=3,则√(x+y)=2当x=-1时,y=3,则√(x+y)=√2
由已知1-x^2>=0x^2-1>=0x^2=1y=3根号x+y=2 或者 根号 2
