题目4单选题
用最速下降法和共轭梯度法求解方程组:<img src="https://tihai-oss-cloud.itihey.com/img/ce2e0bb1c4a20d9fe8993ba479754c18.png">选取(0,0,0)T作为初值,则第二步迭代的搜索方向分别为( )A. 6/55(1,-6,1)T, 114/552(-1,18,-1)TB. 114/552(-1,18,-1)T, 6/55(1,-6,1)TC. 6/55(-1,6,-1)T, 114/552(-1,18,-1)TD. 114/552(-1,18,-1)T, 6/55(-1,6,-1)T