9.计算下列积分:-|||-(1) (int )_(0)^2pi dfrac (1)(5+3sin theta )dtheta ;-|||-(2) (int )_(0)^2pi dfrac ({sin )^2theta }(a+bcos theta )dtheta (agt bgt 0)-|||-(3) (int )_(0)^2pi dfrac (1)({(a+cos theta ))^2}dtheta (agt 1) ;-|||-(4) (int )_(-infty )^+infty dfrac (1)({(1+{x)^2)}^2}dx ;-|||-(5) (int )_(0)^+infty dfrac ({x)^2}(1+{x)^4}dx =-|||-(6) (int )_(-infty )^+infty dfrac (cos x)({x)^2+4x+5}dx-|||-(7) (int )_(-infty )^+infty dfrac (xsin x)(1+{x)^2}dx =-|||-(8) (int )_(0)^+infty dfrac ({x)^2+1}({x)^4+1}dx

48.如果 A2-6A=E，则 A-1=( )。A. -3EB. A+3EC. A+6ED. A-6E

曲线圆度,通常以曲线半径R、切线长T、正矢f的几何关系来检验。A. 正确B. 错误

关于向量组的极大线性无关组，下列说法正确的是（）A. 一个向量组的极大线性无关组是唯一的B. 一个向量组的极大线性无关组可能有多个C. 一个向量组的极大线性无关组的个数等于向量组的秩D. 一个向量组的极大线性无关组的个数等于向量组的维数

9、填空 向量组alpha_(1)=(1,1,2,-2),alpha_(2)=(1,3,-x,-2x),alpha_(3)=(1,-1,6,0)的秩为2，则x=（）.

int dfrac (2{x)^3+2x+3}({x)^2+1}dx=(x)^a+b(x)+C 则 cdot b(x)=

已知(alpha )_(1)=((1,1,2,2))^T, (alpha )_(2)=((1,-1,4,0))^T (alpha )_(3)=((1,0,3,1))^T,(alpha )_(1)=((1,1,2,2))^T, (alpha )_(2)=((1,-1,4,0))^T (alpha )_(3)=((1,0,3,1))^T,则 (alpha )_(1)=((1,1,2,2))^T, (alpha )_(2)=((1,-1,4,0))^T (alpha )_(3)=((1,0,3,1))^T,能由该向量组线性表示的表达式为（） A (alpha )_(1)=((1,1,2,2))^T, (alpha )_(2)=((1,-1,4,0))^T (alpha )_(3)=((1,0,3,1))^T, B(alpha )_(1)=((1,1,2,2))^T, (alpha )_(2)=((1,-1,4,0))^T (alpha )_(3)=((1,0,3,1))^T,

设随机变量X与Y相互独立,且分布律分别为https:/img.zuoyebang.cc/zyb_55f7d6a0a8944a7b9f1cbd29833de468.jpg 0 1-|||-P dfrac (1)(3) dfrac (2)(3)https:/img.zuoyebang.cc/zyb_224303863b46a7a075cb001c204c4bf1.jpg 0 1-|||-P dfrac (1)(3) dfrac (2)(3)求(1)X+Y的分布；(2)X-Y的分布；(3)max(X,Y)的分布； (4)XY的分布;

函数的单调性法:确定函数在定义域(或某个定义域的子集)上的单调性,求出函数的值域。例:求函数在区间上的值域。分析与解答:任取x1 _(2)in (0,+infty ),且,则x1 _(2)in (0,+infty )x1 _(2)in (0,+infty )把x1 _(2)in (0,+infty )代入得:x1 _(2)in (0,+infty )整理得x1 _(2)in (0,+infty )x1 _(2)in (0,+infty )例:设是定义在R上的奇函数,且当x1 _(2)in (0,+infty ),试求函数的.

5.设矩阵 =a(a)^T+b(b)^T, 这里a,b为n维列向量,证明:-|||-(1) (A)leqslant 2.-|||-(2)当a,b线性相关时, (A)leqslant 1.

热门问题