Y=1-根号（X方-3X+2）的单调区间怎么求 首先看定义域 x^2-3x+2》0 => (x-2)(x-1)》0 => x》2.或x《1 又x^2-3x+2=(x^2-3x+9/4)+2-9/4=(x-3/2)^2-1/4 g(x)=x^2-3x+2在（负无穷,1]上单调减,[2,正无穷）上单调增. 所以 Y=1-根号（X方-3X+2） 在（负无穷,1]上单调增,在[2,正无穷)上单调减.
