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Given the sequence {an}, A1 = 1, a (n + 1) = an + 2 / an + 1. Prove that when n is greater than or equal to 2 and N belongs to positive integer, there is 1
prove:
Using mathematical induction
(1) When n = 2,
∵ a1=1
∴ a2=(1+2)/(1+1)=3/2
∴ 1
If A1 = 1, A2 = 6 and an + 2 = an + 1-an, then a2011 is equal to
In addition, in the sequence {an}, A1 = 1, the following items are determined by the formula A1 * A2 * A3 * ······ * an = n, then A3
+A5 equals
Question 2: A1 * A2 * A3 *. * an = n.1
Formula A1 * A2 * A3 *. * an-1 = n-1.2
By subtracting formula 2 from Formula 1, an = n / (n-1) n > = 2 is obtained
So A3 + A5 = 3 / 2 + 5 / 4 = 11 / 4
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