證:
an=2-1/a(n-1)
an - 1= 1 - [1/a(n-1)]=[a(n-1)-1]/a(n-1)
1/(an - 1)=a(n-1)/[a(n-1)-1]=[a(n-1)-1+1]/[a(n-1)-1]=1+1/[a(n-1)-1]
1/(an - 1)-1/[a(n-1)-1]=1,為定值.
1/(a1-1)=1/(3/5-1)=-5/2
bn=1/(an-1)
數(shù)列{bn}是以-5/2為首項,1為公差的等差數(shù)列
已知數(shù)列{an}中,a1=3/5,an=2-1/an-1(n》2),數(shù)列{bn)滿足bn=1/an-1.求證數(shù)列{bn}是等差數(shù)列.
已知數(shù)列{an}中,a1=3/5,an=2-1/an-1(n》2),數(shù)列{bn)滿足bn=1/an-1.求證數(shù)列{bn}是等差數(shù)列.
數(shù)學人氣:143 ℃時間:2019-08-17 22:10:47
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