已知等差数列an,a1=10,d=2,数列an满足bn=(n/2)an-6n,n∈N*
2个回答
an=10+2*(n-1)=8+2n
bn=(n/2)*(8+2n)-6n=n*n+4n-6n=n*n-2n
高中数学忘了,应该是这样吧
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