1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
___________________sinlim0xxxx
设0,0,1)(2xkxxxf,在0x处连续,则________k
曲线xy在)1,1(的切线方程是
答案:2121xy4
设函数52)1(2xxxf,则____________)(xf
答案:x25
设xxxfsin)(,则__________)2π(f
答案:2π(二)单项选择题1
函数212xxxy的连续区间是()答案:DA.),1()1,(B.),2()2,(C.),1()1,2()2,(D.),2()2,(或),1()1,(2
下列极限计算正确的是()答案:BA
1lim0xxxB
1lim0xxxC
11sinlim0xxxD
1sinlimxxx3
设yxlg2,则dy().答案:BA.12dxxB.1dxxln10C.ln10xxdD.1dxx4
若函数f(x)在点x0处可导,则()是错误的.答案:BA.函数f(x)在点x0处有定义B.Axfxx)(lim0,但)(0xfAC.函数f(x)在点x0处连续D.函数f(x)在点x0处可微5
当0x时,下列变量是无穷小量的是()
答案:CA.x2B.xxsinC.)1ln(xD.xcos(三)解答题1.计算极限(1)21123lim221xxxx(2)218665lim222xxxxx2(3)2111lim0xxx(4)3142353lim22xxxxx(5)535sin3sinlim0xxx(6)4)2sin(4lim22xxx2.设函数0sin0,0,1sin)(xxxxaxbxxxf,问:(1)当ba,为何值时,)(xf在0x处有极限存在
(2)当ba,为何值时,)(xf在0x处连续
答案:(1)当1b,a任意时,)(xf在0x处有极限存在;(2)当1ba时,)(