1. ax^2+bx+c=0,求解
ax^2+bx=-c
a[x^2+(b/a)x]=-c
a[x^2+2x*(b/2a)]=-c
a[x^2+(b/a)x+(b/2a)^2]=-c+a*(b/2a)^2
等等,a[x^2+(b/a)x+(b/2a)^2]=-c+a*(b/2a)^2是怎麼來的?
收錄日期: 2021-04-13 18:31:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120213000016KK01280