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(2 / 3) on the straight line X-Y + 2 = 0, find the general term formula of the sequence {an} {BN}. The second question: let CN = anbn, find the first n terms and TN of the sequence {CN}, and (2 / 3) on the straight line X-Y + 2 = 0, find the general term formula of the sequence {an} {BN}. The second question: let CN = anbn, find the first n terms and TN of the sequence {CN}, and satisfy TN
(1)Sn=2An-2
S(n-1)=2A(n-1)-2(n≥2)
Sn-S(n-1)=An=2An-2-[2A(n-1)-2]=2An-2A(n-1)
An=2A(n-1)
First item A1 = S1 = 2a1-2, A1 = 2
So an = 2 * 2 ^ (n-1) = 2 ^ n
Bn-B(n+1)+2=0
B(n+1)=Bn+2
B1=1
So BN = 1 + 2 * (n-1) = 2N-1
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