分类导航
由题意 ?f(x)dx?e?x?C. (2)xf(x)dx?arctanx?C两边求导得 xf(x)? f(x)??1 1?x21 x(1?x2)则 ?111dx??x(1?x2)dx?x2?x4?C. 24f(x) 求下列不定积分 17、(1) ?1x?1dx. dx, (2)?22x?14?2x?xt2?1 【解】(1)令t?2x?1,则x?,dx?tdt 2?13x?1t2?3dx??tdt?t3?t?C 622t2x?1...