1/根号2-1+|根号2-2|+(sin45)-1
=√2/2-1+2-√2+√2
=√2/2+1
(3-x)2+x2=5
x²-6x+9+x²=5
2x²-6x+4=0
x²-3x+2=0
（x-2）（x-1）=0
解得
x1=2,x2=1