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《经济数学》 作业题
第一部分 单项选择题
11.某产品每日的产量是x件,产品的总售价是x2?70x?1100元,每一件的成
21本为(30?x)元,则每天的利润为多少?(A )
31A.x2?40x?1100元
61B.x2?30x?1100元
65C.x2?40x?1100元
65D.x2?30x?1100元
6
2.已知f(x)的定义域是[0,1],求f(x?a)+ f(x?a),0?a?(C )
A.[?a,1?a] B.[a,1?a] C.[a,1?a] D.[?a,1?a]
3.计算limsinkx??( B)
x?0x1的定义域是?2A.0 B.k
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C.
1 kD.?
24.计算lim(1?)x??( C)
x??xA.e
1B.
eC.e2 D.
?ax2?b,???x?2?5.求a,b的取值,使得函数f(x)??1,?????x?2在x?2处连续。(A )
?bx?3,???x?2?1 2e1,b??1 23B.a?,b?1
21C.a?,b?2
23D.a?,b?2
2A.a?
6.试求y?x+x在x?1的导数值为(B )
3A.
25B.
21C.
21D.?
2
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7.设某产品的总成本函数为:C(x)?400?3x?10012,其中xx,需求函数P?2x为产量(假定等于需求量),P为价格,则边际成本为?(B )
A.3 B.3?x C.3?x2
D.3?12x
8.试计算?(x2?2x?4)exdx??(DA.(x2?4x?8)ex B.(x2?4x?8)ex?c C.(x2?4x?8)ex D.(x2?4x?8)ex?c
9.计算?10x21?x2dx??(D )
A.?2 B.?4
C.?8
D.?16
10.计算
x1?1x1?2x??(A )
2?1x2?2A.x1?x2
) B.x1?x2 C.x2?x1 D.2x2?x1
121411.计算行列式D?0?1211013=?(B )
0131A.-8 B.-7 C.-6 D.-5
yxx?y12.行列式
xx?yy=?( B)
x?yyxA.2(x3?y3) B.?2(x3?y3) C.2(x3?y3) D.?2(x3?y3)
??x1?x2?x313.齐次线性方程组??0?x1??x2?x3?0有非零解,则?=?(C??x1?x2?x3?0A.-1 B.0
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C.1 D.2
?0??1976??3B??14.设A??,???0??6?,求AB=?(D ) ??0905??53??76???A.??104110??6084??
B.??104111??6280??
C.??104111??6084??
D.??104111??6284??
?23?15.设A??1?221??,求A?1=?(D ) ??343???132?A.??3?35???2??2? ?11?1??? B.?13?2??35???3? ?22??11?1??