If we know the general term formula of arithmetic sequence {an} an = 3-2n, then its tolerance D is______ ．

If we know the general term formula of arithmetic sequence {an} an = 3-2n, then its tolerance D is______ ．

The general formula of ∵ arithmetic sequence {an} is an = 3-2n, ∵ tolerance d = an + 1-an = [3-2 (n + 1)] - (3-2n) = - 2, so the answer is: - 2

In the sequence {an}, A1 = 0, and for any k ∈ positive integer, a2k-1, a2k + 1 are equal difference sequence, and the tolerance is 2K. (1) prove that A4, A5, A6 are equal ratio sequence
(2) How to find the general term formula of sequence {an}?
A2k-1, a2k, a2k + 1 become arithmetic sequence!

There are only two terms in a (2k - 1) and a (2k + 1)

The tolerance D ≠ 0, a ≠ 0, (n ∈ n +), and {AK} x ^ 2 + 2 {a (K + 1)} x + {a (K + 2)} = 0 (K ∈ n +)
(1) Proof: when k takes different positive integers, this equation has a common root (I have made this question)
(2) If the roots of the equation are different ({X1 /}), then {X1 /}, {X1 /}

It is proved that: (1) from the original formula, (x + 1) [{AK} (x + 1) + 2D] = 0, obviously {XK} = - 1 is the common root (2), then the remaining root is {XK} = - 2D / {AK} - 1, so 1 / ({xn} + 1) = - {an} / 2D = - {A1} / (2D) - (n-1) / 2, so the sequence {1 / ({xn} + 1)} is an arithmetic sequence with the first term - {A1} / (2D) and the tolerance of - 1 / 2