题目

急求2X^3-8X^2+7X+3=0的解
所以需要用初二学过的知识来解,

提问时间：2020-11-13

答案

分解因式分不出来,我在matlab下试了一下,三个根如下,应该是题目出错了吧
x_1=4/3 - (77/108 - (11*432^(1/2))/432)^(1/3) - 11/(18*(77/108 - (11*432^(1/2))/432)^(1/3))
x_2=11/(36*(77/108 - (11*432^(1/2))/432)^(1/3)) + (77/108 - (11*432^(1/2))/432)^(1/3)/2 + 4/3 - (3^(1/2)*(11/(18*(77/108 - (11*432^(1/2))/432)^(1/3)) - (77/108 - (11*432^(1/2))/432)^(1/3))*i)/2
x_3=11/(36*(77/108 - (11*432^(1/2))/432)^(1/3)) + (77/108 - (11*432^(1/2))/432)^(1/3)/2 + 4/3 + (3^(1/2)*(11/(18*(77/108 - (11*432^(1/2))/432)^(1/3)) - (77/108 - (11*432^(1/2))/432)^(1/3))*i)/2