You are Here: Home >< Maths

# proof question Watch

Announcements
1. prove that the (2n+1)th term of the sequence Un=n^2-1 is a multiple of 4.
the answer is at the back of the text book but I dont understand how to answer it.
2. Huuuuulp me plz
3. sub (2n+1) into the n of the sequence, multiply out and simplify - it should hopefully be obvious what to do next once you do this
4. (Original post by KINGYusuf)
So Un=n^2 -1

So U(2n+1) = (2n+1)^2 -1

So U(2n+1) = 4n^2 + 4n

So U(2n+1) = 4(n^2 + n)

therefore a multiple of 4
thanks but why did you multipy (2n+1) by 2-1?
5. (Original post by p29)
thanks but why did you multipy (2n+1) by 2-1?
I just subbed (2n+1) into the nth term that they gave you

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: October 10, 2016
Today on TSR

### Oxbridge

Even more elitist than everyone thought?

### Physically ill after being cheated on

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.