Examples of convergent sequences - exercises

Exercise.

Prove that the sequence ( ) converges to zero when is given by:

(a) (-1) 1 ; (b) 2+2 ; (c) ; (d) +1 ; (e) (+1)3 - 3+3 2 .

(In (c), state precisely what properties of the sine function you are using.)

Exercise.

Let = +1 for =1,2,3, .

State what it means for 1 as and carefully prove this statement.

Exercise.

Stating results from the text where appropriate, show that = defines a convergent sequence for =0 or =1 and a bounded by divergent sequence for =-1.

Exercise.

Let and let = .

(a) Writing =1+ and using Bernoulli's inequality, show that the sequence ( ) does not converge to any real limit when 1 .

(b) Show that the sequence ( ) does not converge to any real limit when -1 .

(Standard results from the course may be used if quoted correctly. In particular, if you don't want to prove the results directly, the idea of a bounded sequence may be helpful.)