Post on 28-Dec-2015
10.2 SequencesMath 6BCalculus II
Limit of Sequences from Limits of Functions
• Suppose f is a function such that for all positive integers n. If , then the limit of the sequence is also L.
Limit Laws for Sequences
• Assume that the sequences and have limits A and B, respectively. Then,
• , where c is a real number
• , provided
Monotonic Sequence
• A sequence {an} is called increasing if an< an+1 for all , that is, a1< a2< a3<…. It is called decreasing if an>an+1. It is called monotonic if it is either increasing or decreasing.
Bounded Sequence
• A sequence {an} is bounded above if there is a number M such that
• It is bounded below if there is a number m such that
• If it is bounded above and below, then {an} is a bounded sequence.
for all 1na M n
for all 1nm a n
Geometric Sequence
• The geometric sequence {r n} will converge if , otherwise the sequence diverges.
Limit Laws and Squeeze Theorem• Squeeze Theorem for Sequences
• Theorem
0If for and lim lim
then limn n n n n n n
n n
a b c n n a c
b L
If lim 0 then lim 0n n n na a
Monotonic Sequence Theorem
• Every bounded, monotonic sequence is convergent.
Limit of a Sequence
• The sequence converges to L provided the terms of can be made arbitrarily close to L by taking n sufficiently large. More precisely, has the unique limit L if given any tolerance , it is possible to find a positive integer N (depending on ) such that where n > N.
Limit of a Sequence
• If the limit of a sequence is L, we say the sequence converges to L, written
• A sequence that does not converge is said to diverge.