a1=1,a2=5,a(N+1)+2an=3a(n-1),设数列cn满足Cn=a(n+1)-an,求证Cn是等比,求Cn

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a1=1,a2=5,a(N+1)+2an=3a(n-1),设数列cn满足Cn=a(n+1)-an,求证Cn是等比,求Cn
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a1=1,a2=5,a(N+1)+2an=3a(n-1),设数列cn满足Cn=a(n+1)-an,求证Cn是等比,求Cn
a1=1,a2=5,a(N+1)+2an=3a(n-1),设数列cn满足Cn=a(n+1)-an,求证Cn是等比,求Cn

a1=1,a2=5,a(N+1)+2an=3a(n-1),设数列cn满足Cn=a(n+1)-an,求证Cn是等比,求Cn
a(N+1)-an+3an=3a(n-1)
a(N+1)-an=3a(n-1)-3an
a(N+1)-an=-3(an-a(n-1))
Cn=-3C(n-1)
所以Cn是等比,且公比为-3
C1=A2-A1=5-1=4
所以Cn=4*(-3)^(n-1)