對(duì)于一元二次方程ax^2+bx+c=0來(lái)說(shuō),若它的兩個(gè)根為x1、x2,則 x1+x2=-b/a x1*x2=c/a 對(duì)于一元三次方程ax^3+bx^2+cx+d=0來(lái)說(shuō),若它的三個(gè)根為x1、x2、x3,則 x1+x2+x3=-b/a 1/x1+1/x2+1/x3=-c/d x1*x2*x3=-d/a 對(duì)于一元n...