交曲线y?f(x)于点C,证明,在(a,b)内至少有一点?,使得f??(?)?0.
第三部分章 一元积分学
一、不定积分
1.单项选择题
(1)下列等式正确的是( )
(A) df(x)dx?f(x); (C) df(x)dx?f(x)dx;
? (B)
df(x)dx?f(x)?C; dx?df(x)dx?f(x)dx. dx?? (D)
(2) 设
?f(x)dx?x?1?C,则f(x)?( )
x?12x; (C) 2; (D) ?2.
(x?1)2(x?1)2(x?1)2?2x(A) 1; (B)
(3) 设f(x)的一个原函数为e(A) ?2e?2x,则
?f?(x)dx?( )
; (B) ?2e?2x?C; (C)?1e?2x; (D)?1e?2x?C. 222.求下列不定积分 (1)
?x?1dx;
2
(2)
??1dx; xdh(g是常数); 2gh (3) (x2?3x?1)dx;
(4)
?xe)dx; (5) ?e(1?xx
2x(6) ?dx; 1?x221?2xdx; (7) ?22x(1?x)
(8) secx(secx?tanx)dx;
? (9)
?1?x21?x4dx;
(10) (2?3)dx;
xx?2 (11)
cos2x?cos2x?sin2xdx;
(12) sin2?xdx; 23.求下列不定积分
(1) (2x?5)10dx;
?
(2) e?3xdx;
? (3)
?11?3xdx;
(5) ?xe?x2dx;
(7)
?1
(arcsinx)21?x2dx; (9) ?cos3xdx;
(11)
?11?cosxdx;
(13) ?sinxcos3xdx; (15) ?x39?x2dx; (17) ?tan3xsecxdx;
(19)
?sinxcosx1?sin4xdx;
(21)
?arctanxx?1?x?dx; (23)
?x2dx(a?0);
a2?x2 (25)
?11?1?x2dx;
4.设f(x)的一个原函数为e?x,计算
?f(lnx)xdx. (4)
?sinxxdx ;
(6)
?x2?3x2dx;
(8)
?1x1?lnxdx;
(10) ?1ex?e?xdx;
(12)
?1?xdx; 1?4x2(14)
?dxsinxcosx;
(16) ?sin2xcos3xdx; (18)
?sinx?cosx3sinx?cosxdx; (20) ?tan1?x2?xdx; 1?x2(22)
?dx(1?x2)3; (24)
?1xx2?1dx;
5.设xf(x)dx?arcsinx?C,计算6.求下列不定积分: xe?2xdx;
??1dx. f(x)?
xsin5xdx;
??lnxdx arccosxdx ??e?xcosxdx
?xln(x?1)dx
?ln(1?x2)dx
?xtan2xdx;
?ln(x?1?x2)dx;
7.求下列不定积分:
⒈
?1x(x2?4)dx;
⒊ ?1x(1?x8)dx; ⒌ ?x2?1x(x?1)2dx;
⒎ ?x2?1(x?1)2(x?1)dx; ⒐
?dxx?4x; ⒒ ?e2x ex?1dx;
⒔ ?1?sinx1?sinxdx;
?(x2?2x?5)e?xdx
?arctan(2x)dx ?(arcsinx)2dx
?cos(lnx)dx; ?ex(1x?lnx)dx;
⒉
?2x?3x2?3x?1dx;
⒋ ?x3x?3dx;
⒍ ?1?x3(1?x2)(1?x2)dx; ⒏
?11?3x?1dx; ⒑
?11?xx1?xdx; ⒓
?cotx1?sinxdx;
⒕ ?sin2x?1cos4xdx; ⒖
1dx; ?3?cosx
⒗
dx?1?sinx?cosx.
二、定积分 ⒈ 试用定积分表示:
⑴ 曲线y?sinx,x?[0,?]与x轴围成的图形的面积
⑵ 曲线y?cosx,x?[0,?]与x轴及x?0,x??所围成的图形的面积 ⒉ 利用定积分的几何意义求下列积分: ⑴
??10a0(x?1)dx;
⑵
?2?1|x|dx;
⑷
⑶
a2?x2dx(a?0)
??sinxdx.
??4. 求f(x)??2t?1dt在[0,1]上的最大值与最小值。 01?t2x
6.计算下列定积分: ⑴
??10(2x2?4x?3)dx;
⑵
1dx; ??11?x21?⑶
40tanxdx;
2 ⑷
??1?1(1?|x|)dx;
⑸
?20x3?2x2?xdx;
⑹
2?0|sinx|dx
?1?2⑺ 设f(x)??1?x?x?0?x?112,求?f(x)dx.
01?x?121x7. 设f(x)在[0,1]上连续,且单调递减,F(x)??f(t)dt,证明在(0,1)内F?(x)?0。
x0?x?1sinx0?x??8. 设f(x)??2,求?(x)??f(t)dt在(??,??)内的表达式。
0?x?0或x???0xx1dt,x?[a,b] 9. 设f(x)?C[a,b],且f(x)?0,x?[a,b],F(x)??f(t)dt??abf(t)证明:⑴F?(x)?2;
⑵方程F(x)?0在(a,b)内有且仅有一个根。 10.计算下列定积分:
1(1)?dx; ; ?2(11?5x)3?1 (2)
????0(1?sin3x)dx;
(3)
1?lnxdx;; ?1xe2?2 (4)
31dx;
2x1?xxdx; 223a?x(5)
??(8?2y2)dy;
(6)
2a0(7)
134dx ; 1?x?1?(8)
??2?cosx?cos3xdx;
2(9)
??03?1?x2x?0,求?f(x?2)dx. 1?cos2xdx (10) 设f(x)???x1x?0?e11.利用函数的奇偶性计算下列积分:
(1)
?10?10(x?100?x)dx;
22 (2)
?121?2(arcsinx)21?x2dx;
32xsinxdx.
(3)?42?5x?3x?1512.证明:
??20cosxdx=?.
4sinx?cosx13.设f?C[a,b],且
?baf(x)dx?1,求
?baf(a?b?x)dx.
14.设f(x)是l以为周期的连续函数,证明:对任意的常数a,有:
?15.设f?C(??,??).证明: (1)若f(x)是奇函数,则16.计算下列定积分 (1)
a?laf(x)dx??f(x)dx
0l?x0(2)若f(x)是偶函数,则?f(t)dt是奇函数. f(t)dt是偶函数;
0x??0xsinxdx ;
(2)
?e1e|lnx|dx;