You are Here: Home >< Maths

# C2 integration watch

1. Hey, I was wondering if someone could help me with this question. The answer to part (i) is k=4

In the second part i got 4/2root2 but the mark scheme says that it is wrong. In the mark scheme they change infinity to 4, but why?
2. What is the answer on the MS?
3. (Original post by Appazap)

Hey, I was wondering if someone could help me with this question. The answer to part (i) is k=4

In the second part i got 4/2root2 but the mark scheme says that it is wrong. In the mark scheme they change infinity to 4, but why?
If you mean you got then this is fine because it is equal to which is the answer.

As for why they change to 4, I don't know. Post the mark scheme.
4. (Original post by TheTechnocrat)
What is the answer on the MS?
just root 2
5. I think it is most likely a misprinted
6. (Original post by Appazap)
just root 2
You just need to rationalise the denominator.
7. (Original post by RDKGames)
If you mean you got then this is fine because it is equal to which is the answer.

As for why they change to 4, I don't know. Post the mark scheme.
oh i feel like an idiot!! have they they just rationalised the denominator then?

also mark scheme
8. (Original post by Appazap)
oh i feel like an idiot!! have they they just rationalised the denominator then?

also mark scheme

Yes.
9. (Original post by Appazap)
oh i feel like an idiot!! have they they just rationalised the denominator then?

also mark scheme
Yes they rationalised the denominator.

What they do in MS is they turn the integral into a proper one with a limit of (which has a different value than in the prev part), then they evaluate the integral in terms of k, then they see what the limit of it is when .
10. (Original post by TheTechnocrat)
Yes.
(Original post by RDKGames)
Yes they rationalised the denominator.

What they do in MS is they turn the integral into a proper one with a limit of (which has a different value than in the prev part), then they evaluate the integral in terms of k, then they see what the limit of it is when .
Thank you all!!

### Related university courses

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: March 13, 2018
Today on TSR

### He broke up with me because of long distance

Now I'm moving to his city

### University open days

Wed, 25 Jul '18
2. University of Buckingham
Wed, 25 Jul '18
3. Bournemouth University
Wed, 1 Aug '18
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