=-cos175=-cos(180-5)=-(-cos5)=cos5 求助得到的回答左边是绝对值,大于等于0所以右边2x-1>=0x>=1/22|2x-4|-3=±(2x-1)2|2x-4|-3=2x-1或2|2x-4|-3=1-2x|2x-4|=x+1或|2x-4|=2-x|2x-4|=x+12x-4=x+1,2x-4=-x-1x=5,x=1|2x-4|=2-x2x-4=2-x,2x-4=x-2x=2,x=2所以三个解和=5+1+2=8
都不是复合函数