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经济数学基础形成性考核册及参考答案
作业( 一)
( 一) 填空题 1.limx?02.设
x?sinx?___________________.答案: 0 x?x2?1,x?0, 在x?0处连续, 则k?________.答案: 1 f(x)???k,x?0?121 23.曲线y?x在(1,1)的切线方程是 .答案: y?x?4.设函数f(x?1)?x2?2x?5, 则f?(x)?____________.答案: 2x 5.设f(x)?xsinx, 则f??()?__________.答案: ?( 二) 单项选择题 1. 函数y?x?1的连续区间是( ) 答案: D
x2?x?2π2π 2A.(??,1)?(1,??) B.(??,?2)?(?2,??)
C.(??,?2)?(?2,1)?(1,??) D.(??,?2)?(?2,??)或(??,1)?(1,??) 2. 下列极限计算正确的是( ) 答案: B A.limx?0xx?1 B.lim?x?0xx?1
C.limxsin?1 D.limx?0x??1xsinx?1 x3. 设y?lg2x, 则dy?( ) .答案: B A.
11ln101dx B.dx C.dx D.dx 2xxln10xx4. 若函数f (x)在点x0处可导, 则( )是错误的.答案: B A.函数f (x)在点x0处有定义 B.xlimf(x)?A, 但A?f(x0)
?x0 C.函数f (x)在点x0处连续 D.函数f (x)在点x0处可微
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5.当x?0时, 下列变量是无穷小量的是( ) . 答案: C A.2x B.(三)解答题 1.计算极限
x2?3x?21(x?2)(x?1)x?2??( 1) lim = = limlim2x?1x?1x?1x?12(x?1)(x?1)(x?1)sinx C.ln(1?x) D.cosx xx2?5x?61(x?2)(x?3)x?3( 2) lim= = = limlimx?2x2?6x?8x?2(x?2)(x?4)x?2(x?4)2( 3) limx?0(1?x?1)(1?x?1)1?x?1=lim x?0xx(1?x?1) =limx?01??x?11=lim??
2x(1?x?1)x?0(1?x?1)35?2x2?3x?5xx?1 ?lim( 4) limx??3x2?2x?4x??2433??2xx( 5) limx?0sin3x5xsin3x33?lim= x?0sin5x3xsin5x55x2?4(x?2)(x?2)( 6) lim?lim?4
x?2sin(x?2)x?2sin(x?2)
1?xsin?b,x?0?x?f(x)??a,x?0,
?sinxx?0?x?2.设函数
问: ( 1) 当a,b为何值时, f(x)在x?0处有极限存在? ( 2) 当a,b为何值时, f(x)在x?0处连续.
答案: ( 1) 当b?1, a任意时, f(x)在x?0处有极限存在;
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( 2) 当a?b?1时, f(x)在x?0处连续。 3.计算下列函数的导数或微分: ( 1) y?x2?2x?log2x?22, 求y? 答案: y??2x?2xln2?( 2) y?1 xln2ax?b, 求y?
cx?d答案: y?=( 3) y?答案: y?a(cx?d)?c(ax?b)ad?cb ?22(cx?d)(cx?d)13x?513x?5, 求y?
=(3x?5) y???12?32(3x?5)3
( 4) y?x?xex, 求y? 答案: y??12x?(x?1)ex
( 5) y?eaxsinbx, 求dy 答案: y??(eax)?sinbx?eax(sinbx)?
?aeaxsinbx?eaxcosbx?b
?eax(asinbx?bcosbx) dy?eax(asinbx?bcosbx)dx
( 6) y?e?xx, 求dy
311答案: dy?(x?2ex)dx
2x1x( 7) y?cosx?e?x, 求dy 答案: dy?(2xe?x?22sinx2x)dx
( 8) y?sinnx?sinnx, 求y?
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答案: y?=nsinn?1xcosx+cosnxn=n(sinn?1xcosx?cosnx) ( 9) y?ln(x?1?x2), 求y? 答
12案
1:
1?11x22??(1?(1?x)2x)y??(x?1?x)?(1?)22222x?1?xx?1?xx?1?x1?x?11?x2
( 10) y?2cot1x?1x1?3x2?2xx3, 求y?
5ln21?21?6??x?x 答案: y?1262xsinx2cot4.下列各方程中y是x的隐函数, 试求y?或dy ( 1) x2?y2?xy?3x?1, 求dy
答案: 解: 方程两边关于X求导: 2x?2yy??y?xy??3?0
(2y?x)y??y?2x?3 , dy?y?3?2xdx
2y?x( 2) sin(x?y)?exy?4x, 求y?
答案: 解: 方程两边关于X求导cos(x?y)(1?y?)?exy(y?xy?)?4
(cos(x?y)?exyx)y??4?yexy?cos(x?y)
4?yexy?cos(x?y) y??xyxe?cos(x?y)5.求下列函数的二阶导数: ( 1) y?ln(1?x2), 求y??
2?2x2答案: y??? 22(1?x)资料内容仅供您学习参考,如有不当或者侵权,请联系改正或者删除。
( 2) y?1?xx, 求y??及y??(1)
533?21?2??答案: y?x?x, y??(1)?1
44作业( 二)
( 一) 填空题
1.若?f(x)dx?2x?2x?c, 则f(x)?___________________.答案: 2xln2?2 2. ?(sinx)?dx?________.答案: sinx?c
3. 若?f(x)dx?F(x)?c, 则?xf(1?x2)dx? .答案: ?F(1?x2)?c 4.设函数
de2ln(1?x)dx?___________.答案: 0 ?1dx0125. 若P(x)??x11?t2dt, 则P?(x)?__________.答案: ?11?x2
( 二) 单项选择题
1. 下列函数中, ( ) 是xsinx的原函数. A.
12122
2
2
2
cosx B.2cosx C.-2cosx
2
D.-cosx 答案: D
2. 下列等式成立的是( ) . A.sinxdx?d(cosx) B.lnxdx?d()
C.2xdx?答案: C
3. 下列不定积分中, 常见分部积分法计算的是( ) .
1d(2x) ln21x D.
1xdx?dx