2023年考研数二真题及解析
2023年全国硕士硕士入学统一考试数学二试题解析一、选择题:1~8小题,每题4分,共32分,下列每题给出的四个选项中,只有一项符合题目要求的,请将所选项前的字母填在答题纸指定位置上.(1)曲线y= \frac {x^{2}+x}{x^{2}-1}新近线的条数为()(A)0(B)1(C)2(D)3(2)设函数f(x)=(e^{x}-1)(e^{2x}-2)(e^{nx}-n),其中n为正整数,则f'(0)=(A)(-1)^{n-1}(n-1)!(B)(-1)^{n}(n-1)!(C)(-1)^{n-1}n! (3)设a_{n}>0(n=1,2, \cdots),S_{n}=a_{1}+a_{2}+\cdots a_{n},则数列(sn)有界是数列(a_{n})收敛的(A)充分必要条件.(B)充分非必要条件.(C)必要非充分条件.(D)即非充分地非必要条件.(4)设I_{k}= \int _{e}^{k}e^{x^{2}} \sin xdx(k=1,2,3),则有D(A)I_{1}<I_{2}<I_{3}.(B)I_{2}<I_{2}<I_{3}.(C)I_{1}<I_{3}<I_{1},(D)I_{1}<I_{2}<I_{3}.(5)设函数f(x,y)可微,且对任意x,y都\frac { \partial f(x,y)}{ \partial x}>0, \frac { \partial f(x,y)}{ \partial y}<0,f(x_{1},y_{1})<f(x2,y2)成立的一种充分条件是(A)x_{1}>x_{2},y_{1}<y_{2}.(B)x_{1}>x_{2},y_{1}>y_{1}.(C)x_{1}<x_{2},y_{1}<y_{2}.(D)x_{1}<x_{2},y_{1}>y_{2}.(6)设区域D由曲线y= \sin x,x= \pm \frac { \pi }{2},y=1,围成,则\int \int(x^{5}y-1)dxdy=()(A)\pi(B)2(C)-2(D)