请用纸写出过程~谢谢

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请用纸写出过程~谢谢
请用纸写出过程~谢谢

 

请用纸写出过程~谢谢
令x1=a,x2=b
由韦达定理a+b=5/3 a*b=-1/3
则a^2+b^2=(a+b)^2-2a*b=31/9
b/a+a/b=(b^2+a^2)/(ab)=(31/9)/(-1/3)=-31/3

由根与系数关系,得
x1+x2=5/3, x1·x2=-1/3
∴(1)x1²+x2²
=(x1+x2)²-2x1·x2
=(5/3)²-2×(-1/3)
=(25/9)+(2/3)
=31/9

x2 x1
(2) ─── + ────

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由根与系数关系,得
x1+x2=5/3, x1·x2=-1/3
∴(1)x1²+x2²
=(x1+x2)²-2x1·x2
=(5/3)²-2×(-1/3)
=(25/9)+(2/3)
=31/9

x2 x1
(2) ─── + ────
x1 x2
x2² x1²
= ──── + ─────
x1·x2 x1·x2
x1²+x2²
= ─────────
x1·x2
(31/9)
= ──────
-(1/3)
= -31/3

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