数值计算方法复习 一、用牛顿法求解方程42( )230fxxxx的解,01.0x ,收敛精度0.001 34212420001020010 '441 23 ,0,1,441231213 =11.1429441441 0.14280.001 nnnnnnnfxxxxxxxxnxxxxxxxxxxx解 :迭 代 格 式424211121231121424222232222231.142921.14291.14293 =11.124544141.142941.14291 0.01840.001231.124521.12451.1 =1441xxxxxxxxxxxxxxxx33224531.124141.124541.12451 0.0003580.001xx 二、应用列主元素消元法求解1230.0012.0003.0001.0001.0003.7124.6232.0002.0001.0725.6433.000xxx 的解,保留 4 位有效数字 0.0012.0003.0001.0002.0001.0725.6433.000 =1.0003.7124.6232.0001.0003.7124.6232.0002.0001.0725.6433.0000.0012.0003.0001.000 A解 :扩 展 矩 阵 如 下 :1.0000.5362.8221.5001.0000.5362.8221.50003.1761.8010.500010.5670.15702.0013.0031.002001.8680.6871.0000.5362.8221.500 010.5670.1570010.368 原 方程 变 换3211.0000.5362.8221.500 010.5670.1570010.3680.3680.05110.499xxxx 为 :求 解 得 到 : 三、应用雅可比迭代法求解下列方程组 1231231231 027 .21 028 .354 .2xxxxxxxxx ,收敛精度0 .0 1 (1 )()()123(1 )()()213(1 )()()312 0 .10 .20 .7 2 0 .10 .20 .8 30 .20 .20 .8 4kkkkkkkkkxxxxxxxxx解 :迭 代 格 式 求解过程如表: k 0 1 2 3 4 5 6 1kx 0 0 .7 2 0 .9 7 1 1 .0 5 7 1 .0 8 5 3 1 .0 9 5 1 1 .0 9 8 3 2kx 0 0 .8 3 1 .0 7 0 1 .1 5 7 1 1 .1 8 5 3 1 .1 9 5 1 1 .1 9 8 3 3kx 0 0 .8 4 1 .1 5 0 1 .2 4 8 2 1 .2 8 2 8 1 .2 9 4 1 1 .2 9 8 ...