绝对值(x-2)+根号x的平方-x+4分之1 根号后边还应该有个括号吧?
=|x-2|+√(x²-x+1/4)
=|x-2|+√(x-1/2)²
=|x-2|+|x-1/2|
=2-x+x-1/2
=3/2