设总体X的分布律为X 1 2 3 _-|||-P α^2 alpha (1-alpha ) ((1-a))^2其中X 1 2 3 _-|||-P α^2 alpha (1-alpha ) ((1-a))^2是非负未知参数，利用总体X的如下样本值1 , 2 , 3 , 2 , 1，试求（1）X 1 2 3 _-|||-P α^2 alpha (1-alpha ) ((1-a))^2的矩估计值；（2）X 1 2 3 _-|||-P α^2 alpha (1-alpha ) ((1-a))^2的最大似然估计值.

设矩阵 =((alpha )_(1),(alpha )_(2),(alpha )_(3),(beta )_(1))，=((alpha )_(1),(alpha

【题目】-|||-设α1,a2,α3线性无关,证明: (alpha )_(1)+(alpha )_(2), (alpha )_(2)+(alpha )_(3),

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=

8 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

6.设α1,α2,α3线性无关, (beta )_(1)=a(alpha )_(1)+b(alpha )_(2) (beta )_(2)=a(alpha )_(

已知 (alpha )_(1)=(1,2,-3), (alpha )_(2)=(2,-1,-1),(alpha )_(1)=(1,2,-3), (alpha )

向量方程((a)_(1)+alpha )-7((alpha )_(2)+alpha )+4(alpha )_(3)=0，其中((a)_(1)+alpha )-7

11 判断设 -t(n) ,如果 (|X|geqslant k)=2alpha , 则 (Xlt k)=1-alpha .-|||-A.X-|||-B.

设向量组(alpha )_(1),(alpha )_(2),(alpha )_(3) 线性无关， (alpha )_(1),(alpha )_(2),(alph

设 alpha (alpha )_(1),(alpha )_(2),(alpha )_(3),(beta )_(1),(beta )_(2) 均为四维列向量矩阵