11.设n阶方阵A的伴随矩阵为A`,证明:-|||-(1) |A|=(|A|)^n-1.-|||-(2) (A)= ) n,R(A)=n, 1,R(A)=n-1, 0,R(A)lt n-1 .-|||-小h

4.计算下列各行列式:-|||-4 1 2 4-|||-1 2 0 2-|||-(1) 10 5 2 0-|||-;-|||-0 1 1 7-|||-2 1 4 1-|||-(2) 3 -1 2 1-|||-1 2 3 2 ;-|||-5 0 6 2-|||-I

【题目】下列命题一定成立的是[](A)若AB=AC,则B=C(B)若AB=O,则A.=O或B.=O(C.)若A≠O,则|A|≠0(D.)若|A|≠0,则A≠O

(5) lim _(narrow infty )dfrac ({(-2))^n+(3)^n}({(-2))^n+1+(3)^n+1} ,

计算极限 lim _(xarrow 0)dfrac ({int )_(0)^xsin tdt}({x)^2} ()-|||-A.1 B. 1/2 C.0 D. -1-|||-__

已知向量组(I)α1,α2,α3;(Ⅱ)α1,a2,a3,a4;(Ⅲ)α1,α2,α3,α5,如果它们的秩分别为-|||-(I)=r(II)=3 (m)=4, 求 ((alpha )_(1),(alpha )_(2),(alpha )_(3),(a)_(4)+(a)_(5)).

曲线y = x^3 - 3x上切线平行于x轴的点是（ ）。A. (0，0)B. (1，2)C. (-1，2)D. (-1，-2)

设矩阵A= 2 1-|||--1 2,E为2阶单位矩阵,矩阵B满足BA=B+2E,则|B|=_____.

lim_(x arrow ∞) (x^2+x)/(x^4-3x^2+1)

29.由下列各已知调和函数求解析函数 f(z)=u+iv =-|||-(1) =(x-y)((x)^2+4xy+(y)^2) ;-|||-(2) =dfrac (y)({x)^2+(y)^2} f(2)=0 ;-|||-(3) u=2(x-1)y f(2)=-i ;-|||-(4) =arctan dfrac (y)(x),xgt 0 -

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