复变函数考试题及答案
一、单项选择题(每题2分,共20分)
1.函数\(f(z)=z^2\)在复平面上()
A.处处不可导B.仅在原点可导C.处处可导D.仅在实轴上可导
2.复数\(z=3+4i\)的模\(\vertz\vert\)为()
A.3B.4C.5D.7
3.若\(f(z)\)在区域\(D\)内解析,且\(f^\prime(z)=0\),则\(f(z)\)在\(D\)内()
A.为常数B.为线性函数C.为二次函数D.不确定
4.积分\(\oint_{|z|=1}\frac{1}{z}dz\)的值为()
A.\(0\)B.\(2\pii\)C.\(\pii\)D.\(-2\pii\)
5.函数\(f(z)=\frac{1}{z-1}\)在\(z=2\)处的泰勒展开式的收敛半径为()
A.1B.2C.3D.\(\infty\)
6.下列函数中,在整个复平面解析的是()
A.\(\frac{1}{z}\)B.\(\overline{z}\)C.\(e^z\)D.\(\lnz\)
7.复数\(z=-1+i\)的辐角主值\(\argz\)为()
A.\(\frac{\pi}{4}\)B.\(\frac{3\pi}{4}\)C.\(\frac{5\pi}{4}\)D.\(\frac{7\pi}{4}\)
8.设\(f(z)\)在单连通区域\(D\)内解析,\(C\)为\(D\)内的一条简单闭曲线,则\(\oint_{C}f^\prime(z)dz\)等于()
A.\(f(z)\)B.\(0\)C.\(f^\prime(z)\)D.\(2\piif(z)\)
9.函数\(f(z)=\frac{1}{z^2+1}\)的奇点为()
A.\(z=i\)B.\(z=-i\)C.\(z=\pmi\)D.\(z=1\)
10.幂级数\(\sum_{n=0}^{\infty}z^n\)的收敛域是()
A.\(\vertz\vert\lt1\)B.\(\vertz\vert\leq1\)C.\(\vertz\vert\gt1\)D.整个复平面
答案:1.C2.C3.A4.B5.A6.C7.B8.B9.C10.A
二、多项选择题(每题2分,共20分)
1.以下哪些是解析函数的等价条件()
A.满足柯西-黎曼方程B.可微C.可导D.具有任意阶导数
2.下列关于复数运算正确的有()
A.\((a+bi)+(c+di)=(a+c)+(b+d)i\)B.\((a+bi)(c+di)=(ac-bd)+(ad+bc)i\)
C.\(\frac{a+bi}{c+di}=\frac{(a+bi)(c-di)}{c^2+d^2}\)D.\(\vertz_1z_2\vert=\vertz_1\vert\vertz_2\vert\)
3.函数\(f(z)\)在点\(z_0\)解析的充分条件有()
A.\(f(z)\)在\(z_0\)的某邻域内可展成幂级数B.\(f(z)\)在\(z_0\)连续
C.\(f(z)\)在\(z_0\)的某邻域内满足柯西-黎曼方程D.\(f(z)\)在\(z_0\)可导
4.下列哪些是复变函数的积分性质()
A.\(\oint_{C}kf(z)dz=k\oint_{C}f(z)dz\)(\(k\)为常数)B.\(\oint_{C}(f(z)+g(z))dz=\oint_{C}f(z)dz+\oint_{C}g(z)dz\)
C.\(\oint_{C}f(z)dz=-\oint_{-C}f(z)dz\)D.\(\vert\oint_{C}f(z)dz\vert\leqML\)(\(M\)为\(\vertf(z)\vert\)在\(C\)上的最大值,\(L\)为\(C\)的长度)
5.关于幂级数\(\sum_{n=0}^{\infty}a_n(z-z_0)^n\),下列说法正确的是()
A.存在收敛半径\(R\)B.在收敛圆内绝对收敛
C.在收敛圆外发散D.在收敛圆周上一定发散
6.函数\(f(z)=\frac{1}{(z-1