x Turn on thread page Beta
 You are Here: Home >< Maths

# FP3 reduction question watch

1. In=(limits between 0 and 1) ∫1/(x²+a²)n dx where a and n are constants and a≠0
a) Show that for n≠0, 2na²I[n+1]=(2n-1)In+(1+a²)-n

No idea how to get started although maybe using a substitution somewhere?
2. (Original post by bobbricks)
In=∫1/(x²+a²)n dx where a and n are constants and a≠0
a) Show that for n≠0, 2na²I[n+1]=(2n-1)In+(1+a²)-n

No idea how to get started although maybe using a substitution somewhere?
write as 1 . (x2 + a2)-n and use parts

it is very quick
3. Okay, cheers
The next part b) :
Use this integral to evaluate a=2 and n=5/2

Stuck on this now
4. (Original post by bobbricks)
Okay, cheers
The next part b) :
Use this integral to evaluate a=2 and n=5/2

Stuck on this now
Do you mean?
"Use this reduction formula with a=2 and n=5/2 ...

surely you cannot be stuck at this ... this is just number-crunching
5. (Original post by bobbricks)
Okay, cheers
The next part b) :
Use this integral to evaluate a=2 and n=5/2

Stuck on this now

(Original post by TeeEm)
Do you mean?
"Use this reduction formula with a=2 and n=5/2 ...

surely you cannot be stuck at this ... this is just number-crunching
you may some fully solved examples useful in this link

6. (Original post by TeeEm)
Do you mean?
"Use this reduction formula with a=2 and n=5/2 ...

surely you cannot be stuck at this ... this is just number-crunching
I'd sub in those values but I can't see how this simplifies it because of the "n+1" which doesn't 'reduce' the integrals
7. (Original post by bobbricks)
I'd sub in those values but I can't see how this simplifies it because of the "n+1" which doesn't 'reduce' the integrals
look at some applications in the link I gave you
8. (Original post by bobbricks)
I'd sub in those values but I can't see how this simplifies it because of the "n+1" which doesn't 'reduce' the integrals
9. (Original post by dandroff)
NOT for phones
10. (Original post by TeeEm)
NOT for phones
how do i view it on PDF?? sorry
11. (Original post by dandroff)
how do i view it on PDF?? sorry
12. (Original post by TeeEm)
im so sorry for asking again but how do i download the file from the site?? it doesnt let me click anything on it

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: June 3, 2015
Today on TSR

### Any tips for freshers...

who are introverts?

### More snow?!

Discussions on TSR

• Latest
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

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