# Sequence and Series

• June 10th 2012, 04:43 PM
Sequence and Series
Hey i just joined here.
am stuck on this question:

A sequence A(n) is defined by A(n)= (n+4)/2n
a.)Prove that the sequence is bounded below by 1/2(Thinking)
• June 10th 2012, 05:03 PM
Plato
Re: Sequence and Series
Quote:

Hey i just joined here.
am stuck on this question:

A sequence A(n) is defined by A(n)= (n+4)/2n
a.)Prove that the sequence is bounded below by 1/2

You can prove this by induction.
$A(1)=\frac{1+4}{2\cdot 1}=\frac{5}{2}$
• June 11th 2012, 12:11 AM
biffboy
Re: Sequence and Series
Quote:

Hey i just joined here.
am stuck on this question:

A sequence A(n) is defined by A(n)= (n+4)/2n
a.)Prove that the sequence is bounded below by 1/2(Thinking)

A(n)==(n+4)/2n = (1/2)+2/n
• June 11th 2012, 02:00 AM
Re: Sequence and Series
Could you explain...
• June 11th 2012, 03:05 AM
biffboy
Re: Sequence and Series
n is a positive integer so !/2 + 4/n is always greater than 1/2 but increasing n makes it closer and closer to 1/2
• June 11th 2012, 03:10 AM
biffboy
Re: Sequence and Series
n is a positive integer so 1/2+2/n is always greater than 1/2 but gets closer and closer to 1/2 as n increases
• June 11th 2012, 10:48 PM