BOUNDED SEQUENCE

Definition:

  • A sequence (an) set to be bounded above if there exists a real number k such that an<=k for all n belongs to N then k is called upper bound of the sequence (an).

  • A sequence (an) set to be bounded below if there exists a real number such that an>=k for all n belongs to N then k is called lower bound of a sequence (an).
  • A sequence (an) is set to be bounded sequence if it is bounded above and bounded below .
  • A sequence (an) set to be bounded if there is a real number k such that mod an<=k for all n belongs to N. 

Examples:

i) Consider the sequences 1,1/2,1/3,....1/n,....   Here, 1 is the least upper bound and 0 is the Greatest         lower bound.   Therefore, it is a bounded sequence.

ii)  The sequence 1,2,3,...,n,..... bounded below is 1, but not bounded above, Greatest lower bound is         1.

iii)  Any constant sequences is a bounded sequences.  Here, least upper bound=Greatest lower bound,
        the constant term of the sequence.

iv)  1,-1,1,-1,.... is a bounded sequence, upper bound is 1, lower bound is -1, least upper bound is 1,            greatest lower bound is -1.
Previous
Next Post »