Let’s applytheserulesto help us find limits.
Example 11
Find.
Solution
We coulduse L’Hôpital’s rule or we coulduse someof the rulesin the precedingtheorem.Let’s use the
rulesin the theorem.Divideboth the numeratorand denominatorby the highestpowerofnin the expression
and usingrulesfrom the theorem,we find the limit:
Dividingboth numeratorand denominatorbyn
Simplifying
Applyingthe divisionrule for limits.
Applyingthe rule for the limit of a sum to the denominator
Evaluatingthe limits
Example 12
Find.
Solution
Applyingthe rule for the differenceof two limits
Applyingthe rule for the limit of c timesa limit
Evaluatingthe limits
As with limitsof functions,thereis a Sandwich/SqueezeTheoremfor the limitsof sequences.
Sandwich/SqueezeTheoremLet {an}, {bn} and {cn} be sequences.LetNbe a positivein-
teger. Supposecnis a sequencesuchthatan≤cn≤bnfor alln≥N. Supposealso that
. Then.