1、2019/11/6,1,线性代数第2讲,作业的问题,2019/11/6,2,作业的问题,作业中最大的问题就是, 许多学生并没有将方程的增广矩阵, 经过一系列行初等变换后, 变化成行简化阶梯矩阵, 将任何一个矩阵经过一系列行初等变换, 变化成行简化阶梯矩阵, 是线性代数的基本技术, 一定要掌握.,2019/11/6,3,行简化阶梯矩阵的例:,2019/11/6,4,不是行简化阶梯矩阵的例:,2019/11/6,5,不是行简化阶梯矩阵的例:,2019/11/6,6,不是行简化阶梯矩阵的例:,2019/11/6,7,不是行简化阶梯矩阵的例:,2019/11/6,8,习题1,2019/11/6,9,2
2、019/11/6,10,2019/11/6,11,2019/11/6,12,2019/11/6,13,2019/11/6,14,2019/11/6,15,2019/11/6,16,2019/11/6,17,习题2,2019/11/6,18,2019/11/6,19,2019/11/6,20,2019/11/6,21,2019/11/6,22,2019/11/6,23,2019/11/6,24,习题3,2019/11/6,25,2019/11/6,26,2019/11/6,27,2019/11/6,28,2019/11/6,29,2019/11/6,30,方程无解,2019/11/6,31,习题
3、4,2019/11/6,32,2019/11/6,33,2019/11/6,34,2019/11/6,35,2019/11/6,36,2019/11/6,37,2019/11/6,38,k是任意常数,2019/11/6,39,习题5,2019/11/6,40,2019/11/6,41,2019/11/6,42,当p = -2时,方程无解,2019/11/6,43,当p -2时,2019/11/6,44,2019/11/6,45,2019/11/6,46,2019/11/6,47,如p=1, 则,方程有无穷多解, 令x2=k1, x3=k2, k1,k2为任意常数,则x1=1-k1-k2, 方程
4、的解为1-k1-k2, k1, k2,2019/11/6,48,如p1且p-2则,2019/11/6,49,2019/11/6,50,由,可得方程有唯一解,2019/11/6,51,习题6,2019/11/6,52,2019/11/6,53,2019/11/6,54,2019/11/6,55,2019/11/6,56,2019/11/6,57,当p2时, 无论q取何值, 方程都有唯一解. 如p=2, 则,这时如q2, 方程无解,2019/11/6,58,如p=2, q=2,2019/11/6,59,如p=2, q=2,2019/11/6,60,方程有无穷多组解, x3为自由变元, 令x3=k, k为任意常数, 则,2019/11/6,61,如p2, 方程有唯一解, 这时,2019/11/6,62,2019/11/6,63,今天作业: 重做1,2,3,4题 5,6题,
