x2-2x+5 x+5)+2|√(x-1)2+4ax (x2-2x+5)2+(x-1) 4In(x-1 2x+5) Ex= xxdxx x dx ∫ ∫ +−++−+− 4)1(2)52(52 2 1 2 2 2 = xxxxx )521ln(452)1()52( ++−+−++−−++−= cxxx 3 1 2 2 2 3 2 . Ex [1]P254—255 3，4，5； [4]P257 90，91. 98