【单选题】在求线性方程组特解的过程中,可以用( )将增广矩阵化成行最简形。
【判断题】行最简形矩阵的特点是:非零行的第一个非零元素为1,且这些零元所在的列的其他元素都为0.
【判断题】分析以下关于MATLAB命令的描述:1.det(A)是计算方阵A行列式的值;2.rref(A)是对矩阵A进行初等行变换化为行最简形;3.A^-1和Inv(A)都是计算A的逆矩阵;4.eig(A)是计算A的特征值;5.rank(A)是计算A的秩;6.A^3是计算A3;7.A’*B是计算ATB;8.null(A,’r’)是计算Ax=0的基础解系。以上描述是否正确?
【多选题】关于工程项目管理组织形式的特点,下列说法正确的有( )。
D.
职能式组织主要是发挥职能人员作用,从职能角度对项目进行管理
【判断题】Asked if they would stay aboard, the programmers did not even trust themselves and said they would disembark immediately.
【多选题】若一个矩阵具有如下特征就称之为行最简形矩阵:
【单选题】听力原文:W: Have you asked Henry and his wife if they would come over for dinner at the weekend? M: I have dialed their number repeatedly but kept getting a busy signal. What does the woman imply?. (14)
A.
They haven't received the invitation yet.
B.
They won't be flee at the weekend.
C.
They are expected to come to the dinner.
D.
They haven't replied so far.