《经济数学基础12》形成性考核册及参考答案
作业(一)
(一)填空题
1.limx?sinxx?___________________.答案:0 x?02.设
f(x)???x2?1,x?0?,在x?0处连续,则k?________.答案:1 ?k,x?03.曲线
y?x在(1,1)的切线方程是 .答案:y?112x?2 4.设函数f(x?1)?x2?2x?5,则f?(x)?____________.答案:2x
5.设
f(x)?xsinx,则f??(π2)?__________.答案:?π2
(二)单项选择题 1. 函数
y?x?1x2?x?2的连续区间是( )答案:D A.(??,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.limxxx?0x?1 B.limx?0?x?1
C.lim1x?0xsinx?1 D.limsinxx??x?1
3. 设
y?lg2x,则dy?(
).答案:B
A.
12xdx B.1xln10dx C.ln10xdx D.1xdx 4. 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.
xlim,但?xf(x)?AA?f(x0)0 C.函数f (x)在点x0处连续 D.函数f (x)在点x0处可微 5.当x?0时,下列变量是无穷小量的是( ). 答案:C A.2x B.sinxx C.ln(1?x) D.cosx (三)解答题 1.计算极限
(1)limx2?3x?21x2?5x?x?1x2?1??2 (2)lim61x?2x2?6x?8?2 (3)lim1?x?1x?0x??12 (4)limx2?3x?51x??3x2?2x?4?3 (5)limsin3xx?0sin5x?35 (6)limx2?4x?2sin(x?2)?4
??xsin1?b,x?02.设函数
f(x)??x?a,x?0,
??sinx?xx?0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;(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?1xln2
(2)y?ax?bcx?d,求y?
答案:y??ad?cb(cx?d)2
(3)
y?13x?5,求
y?
答案:
y???32(3x?5)3
(4)
y?x?xex,求y?
答案:
y??1x2x?(x?1)e
(5)
y?eaxsinbx,求dy
答案:dy?eax(asinbx?bcosbx)dx1(6)
y?ex?xx,求dy
答案:dy?(112x?1xx2e)dx (7)
y?cosx?e?x2,求dy
答案:dy?(2xe?x2?sinx2x)dx
(8)
y?sinnx?sinnx,求y? 答案:
y??n(sinn?1xcosx?cosnx)
(9)
y?ln(x?1?x2),求y?
答案:y??11?x2
cot13(10)
y?2x?1?x2?2xx,求
y?
1x答案:y??2cotln25?1x?32?1x?6 x2sin126x4.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:dy?y?3?2x2y?xdx (2)sin(x?y)?exy?4x,求y?
答案:y??4?yexy?cos(x?y)xexy?cos(x?y) 5.求下列函数的二阶导数: (1)
y?ln(1?x2),求y??
答案:y???2?2x2(1?x2)2
(2)
y?1?xx,求
y??及y??(1)
5答案:y???3?324x?14x?2,y??(1)?1 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:
?12F(1?x2)?c 4.设函数dedx?1ln(1?x2)dx?___________.答案:0 5. 若P(x)??01xt1?t2d,则P?(x)?__________.答案:?11?x2
(二)单项选择题
1. 下列函数中,( )是xsinx2
的原函数. A.
1cosx2
B.2cosx2
2 C.-2cosx2
D.-12cosx2
答案:D
2. 下列等式成立的是( ). A.sinxdx?d(cosx) B.lnxdx?d(1x)
C.2xdx?11ln2d(2x) D.
xdx?dx 答案:C
3. 下列不定积分中,常用分部积分法计算的是( ). A.?cos(2x?1)dx, B.?x1?x2dx C.
?xsin2xdx
D.
?x1?x2dx
答案:C
4. 下列定积分计算正确的是( ). A.
?1?12xdx?2 B.?16?1dx?15
C.??x3)dx?0 D.????(x2???sinxdx?0
答案:D
5. 下列无穷积分中收敛的是( ). ??1??A.
?1?1xdx B.?1x2dx C.??0exdx D.???1sinxdx 答案:B
(三)解答题
1.计算下列不定积分
?3x(1)exdx
3x答案:
ex?c ln3e(2)
?(1?x)2xdx
答案:2x?433x2?255x2?c(3)?x2?4x?2dx 答案:
12x2?2x?c (4)?11?2xdx
答案:?12ln1?2x?c
(5)
?x2?x2dx
答案:1323(2?x)2?c
(6)
?sinxxdx
答案:?2cosx?c
(7)
?xsinx2dx
答案:?2xcosx2?4sinx2?c(8)
?ln(x?1)dx
答案:(x?1)ln(x?1)?x?c
2.计算下列定积分 (1)
?2?11?xdx
答案:
52 12(2)
?ex1x2dx 答案:e?e
3)
?e3(11x1?lnxdx
答案:2
?(4)
?20xcos2xdx
答案:?12 (5)
?e1xlnxdx
答案:14(e2?1) (6)
?40(1?xe?x)dx
答案:5?5e?4
作业三 (一)填空题
??104?5?1.设矩阵
A??3?232????216?1??a23?__________________.答案:3
,则
A的元素