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

# OCR MEI FP2 Thread - AM 27th June 2016 watch

1. (Original post by Connorbwfc)
1/2 ln (2x/5 + root(4x^2/25 + 1) is my answer.

The answer in the guidance section is ln (2x/5 + root(4x^2/25 + 1)

Isn't this my answer without the 1/2 infront of it?
Oh yeah sorry I didn't notice that, I'm not sure, maybe make a thread asking the question if no one else responds as someone will surely know the answer
2. (Original post by Alex621)
Oh yeah sorry I didn't notice that, I'm not sure, maybe make a thread asking the question if no one else responds as someone will surely know the answer
Please could you attempt the question and see what answer you get...

I've asked my friend and they also get the same answer as me.
3. I'm probably just being really stupid but how do you integrate the 1/(pi + theta)^2 part? Thanks
Attached Images

4. (Original post by Connorbwfc)
Please could you attempt the question and see what answer you get...

I've asked my friend and they also get the same answer as me.
Usually I integrate into the form arsinh(x/a), then convert to ln, and that gave me the same answer as you, with the 1/2 at the front, but I just tried integrating straight into ln form, using the formula in the booklet in the integration table, rather than the formula on the next page and I got the answer in the mark scheme, I'm really confused too now...
5. (Original post by Alex621)
I'm probably just being really stupid but how do you integrate the 1/(pi + theta)^2 part? Thanks
It's just basic integration rules. So it's like integrating (Pi + theta)^-2, so you increase the power to -1 and then divide by the new power (-1).
6. (Original post by Connorbwfc)
It's just basic integration rules. So it's like integrating (Pi + theta)^-2, so you increase the power to -1 and then divide by the new power (-1).
Oh right ok thanks I haven't done any basic C4 integration for ages
7. Could anyone help me with june 13 4IV, I tried intergrating by parts but I just end up going in a loops really confused

Posted from TSR Mobile
8. (Original post by HFancy1997)
Could anyone help me with june 13 4IV, I tried intergrating by parts but I just end up going in a loops really confused

Posted from TSR Mobile
If you write out the whole integration by parts formula, on the LHS you have the original integral, and on RHS you have the negative of it, add it onto the LHS, then you have 2x(the original integral) so divide both sides by two, and then continue
9. (Original post by Alex621)
If you write out the whole integration by parts formula, on the LHS you have the original integral, and on RHS you have the negative of it, add it onto the LHS, then you have 2x(the original integral) so divide both sides by two, and then continue
I dont quite understand what you mean

Posted from TSR Mobile
10. (Original post by HFancy1997)
I dont quite understand what you mean

Posted from TSR Mobile
-
11. In the eigenvector question in jan 13, i got all the 3 eigenvalues correct and one eigenvector correct but the other two i got the ones in the mark scheme but with the signs switched? Does the signs matter in the eigenvector even if theyre compatible with sim equations you derived?
Attached Images

12. (Original post by groovy_q)
In the eigenvector question in jan 13, i got all the 3 eigenvalues correct and one eigenvector correct but the other two i got the ones in the mark scheme but with the signs switched? Does the signs matter in the eigenvector even if theyre compatible with sim equations you derived?
Doesn't matter if they work.
13. (Original post by Alex621)
-
Oh wow didnt know this was a thing! Thanks man

Posted from TSR Mobile
14. (Original post by groovy_q)
In the eigenvector question in jan 13, i got all the 3 eigenvalues correct and one eigenvector correct but the other two i got the ones in the mark scheme but with the signs switched? Does the signs matter in the eigenvector even if theyre compatible with sim equations you derived?
Generally signs don't matter but you should give the. In the simplest form. Thsi means in a 3x3 matrix you should always have at least 2 positives in the eigenvalues vector but in a 2x2 matrix it doesn't matter.
15. (Original post by Alex621)
I'm probably just being really stupid but how do you integrate the 1/(pi + theta)^2 part? Thanks
I used substitution for this, dont understand what the mark scheme did but substitution worked

Posted from TSR Mobile
16. (Original post by Aph)
Generally signs don't matter but you should give the. In the simplest form. Thsi means in a 3x3 matrix you should always have at least 2 positives in the eigenvalues vector but in a 2x2 matrix it doesn't matter.
In my answer i had two positive values in the eigenvector and the answer in the mark scheme only had 1? Theres also nothing from that mark scheme that suggests ignore the sign so im pretty worried haha
17. (Original post by groovy_q)
In my answer i had two positive values in the eigenvector and the answer in the mark scheme only had 1? Theres also nothing from that mark scheme that suggests ignore the sign so im pretty worried haha
I wouldn't worry then. Both are generally correct but my guess would be that examiner didn't think about simplification. You'd get the marks

Posted from TSR Mobile
19. (Original post by Connorbwfc)
1/2 ln (2x/5 + root(4x^2/25 + 1) is my answer.

The answer in the guidance section is ln (2x/5 + root(4x^2/25 + 1)

Isn't this my answer without the 1/2 infront of it?
I'm guessing you did something like factor out from the original integral, and then had and ?

So
20. Quick question: When plotting points on an Argand diagram do you have to draw lines to the point from the origin? This is usually when plotting the roots of a complex number.

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: December 6, 2017
Today on TSR

### Boyfriend slept with someone else

...we were on a break

### Mum says she'll curse me if I don't go to uni

Poll
Useful resources

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups

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