How can I prove that n/(n+1) = 1-[1/(n+1)]?

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Homework Help Overview

The discussion revolves around proving the equality of two expressions: n/(n+1) and 1 - [1/(n+1)]. The subject area pertains to sequences and series, particularly focusing on algebraic manipulation and proof techniques.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss methods for manipulating the first expression to show its equivalence to the second. One participant suggests rewriting n/(n+1) in a different form to facilitate comparison. Others consider starting from the second expression to derive the first.

Discussion Status

The conversation includes hints and suggestions for approaching the problem, with some participants expressing appreciation for the guidance provided. There is an ongoing exploration of different methods to prove the equality, but no consensus has been reached on a specific approach.

Contextual Notes

Participants mention the challenge of manipulating fractions and the importance of common denominators in their reasoning. There is an acknowledgment of the simplicity of the task, yet difficulty in execution.

red_hockey
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I am beginning to teach myself series/sequences but I keep running into issues getting started.

A common example I keep seeing is: n/(n+1)
This almost always gets set to: 1 - [1/(n+1)]

I have tried to work out the proof of this myself, but I can't seem to get the two to equal each other/manipulate the first to equal the second.

Could someone point me towards what i have to do to the first fraction? Should be an easy thing but I can't put my finger on it.
 
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Hey,

write n/(n+1) as ((n+1)-1)/(n+1)

What do you see?
 
ooohhhhhhh
thanks a lot, very helpful, good hint.
 
red_hockey said:
I have tried to work out the proof of this myself, but I can't seem to get the two to equal each other/manipulate the first to equal the second.

Could someone point me towards what i have to do to the first fraction? Should be an easy thing but I can't put my finger on it.

The easier way of proving this would be to work with the second fraction, then hopefully come up with how you can reverse the procedure.
Why we want to work with the end result is because the first fraction is just one fraction, which means to get from

[tex]1-\frac{1}{n+1}[/tex] to [tex]\frac{n}{n+1}[/tex] we need to start by taking the common denominator, that is, putting the fraction all under the same denominator.
 

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