It is known that the sum of the first three terms of the arithmetic sequence {an} is - 3, and the product of the first three terms is 8

It is known that the sum of the first three terms of the arithmetic sequence {an} is - 3, and the product of the first three terms is 8

Let the first three terms of the arithmetic sequence {an} be A-D, a, a + D respectively, then we can get a − D + A + D = − 3 (a − d) a (a + D) = 8 from the title meaning, and the solution is a = − 1D = − 3 or a = − 1D = 3. When a = - 1, d = - 3, the first term A1 = A-D = - 1 - (- 3) = 2, the general term formula of the arithmetic sequence {an} is an = 2-3 (n-1) = 5-3n

It is known that the sum of the first three terms of the arithmetic sequence {an} is - 3, and the product of the first three terms is 8,
Find the general formula of {an}
If a 2, a 3 and a 1 are equal ratio sequence, find the sum of the first n terms of sequence {an}

(1) If the sum of the first three terms of the arithmetic sequence {an} is - 3, then A2 = - 3 ／ 3 = - 1, let the tolerance of the sequence be D, the first three terms be - 1-D, - 1, - 1 + D, and the product is 8, with (- 1-D) × (- 1) × (- 1 + D) = 8, then D & # 178; = 9, and d = 3 or D = - 3. Thus, the first three terms are: - 4, - 1,2 or 2, - 1, - 4, and {an}