Question

这个,答案算出来了,希望专家给个正解.

Answer 1

x1+x2=-p x1*x2=q

(1)x1^2+3x1x2+x2^2

=(x1+x2)^2+x1x2

=p^2+q=1 .(i)

(2)x1+1/x1+x2+1/x2

=x1+x2+(x1+x2)/x1x2

=-p-p/q=0 .(ii)

(3)由(i)(ii)得

p+p/q=0

p(1+1/q)=0

得p=1 或1+1/q=0 => q=-1

所以i.p=1 q=0

ii.q=-1 p=0

有上述两解