Edexcel FP1 Thread - 20th May, 2016

Then its alright! :smile:

Are you sure? because I can't find the method in any mark scheme so I'm afraid the examiner will mark it wrong because it's not a way of doing it that's accepted by the mark scheme :/

Reply 801

anujsr

3

Original post by TheMoon

Are you sure? because I can't find the method in any mark scheme so I'm afraid the examiner will mark it wrong because it's not a way of doing it that's accepted by the mark scheme :/

Then to be safe, if you still have time practice using the accepted method. Hopefully it will work out.

Reply 802

anujsr

3

Original post by anujsr

Then to be safe, if you still have time practice using the accepted method. Hopefully it will work out.

If you have the edexcel textbook it is one of the proofs in topic 6

Reply 803

crashMATHS

16

Original post by TheMoon

Are you sure? because I can't find the method in any mark scheme so I'm afraid the examiner will mark it wrong because it's not a way of doing it that's accepted by the mark scheme :/

Yeah, there's a range of alternative methods listed every year - yours is one of them. If you do the proof correctly, then you will get full marks

Reply 804

anujsr

3

Original post by Windowswind123

Usually around the hour mark.

Thanks, just wanted to know so that i can finish on time. Usually i start lagging behind when i do questions too slowly

Reply 805

iMacJack

16

Any help with this proof by induction question please? Thanks!

@Zacken @NotNotBatman @kingaaran etc! Thank you!

Question from CM PBI worksheet

This one is pretty difficult and took me a while, I doubt we would get this in the exam just because it is rather horrible.

Posted from TSR Mobile

Reply 807

Windowswind123

2

Original post by anujsr

Thanks, just wanted to know so that i can finish on time. Usually i start lagging behind when i do questions too slowly

Good luck - I was really worried about M3 for timing but I managed to finish that in an hour.
Still stressed about D1 timing though - sure that should be two hours :biggrin:

Reply 808

indecisiveness

7

Hi can someone explain how matrix rotation work for multiples of 45°? Thank youu

Reply 809

tazza ma razza

19

Original post by TheMoon

This is the method I'm talking about, I've seen it in the textbook so I thought it would be allowed:

^this was from the textbook "review 2" solutions.

ahhhh good to see my go to method for divsivion proofs - get it right every single time espicially if the question comes at the end of the paper! Unless of course it is like a question 2 or 3 proof where you can use the f(k+1) -f(k) method

Reply 810

iMacJack

16

Original post by alfmeister

This one is pretty difficult and took me a while, I doubt we would get this in the exam just because it is rather horrible.

Posted from TSR Mobile

My neck hurts now!

Reply 811

Zacken

22

Original post by iMacJack

Any help with this proof by induction question please? Thanks!

@Zacken @NotNotBatman @kingaaran etc! Thank you!

Question from CM PBI worksheet

Normal divisibility (by 3). Consider

f(k+1) - f(k)

. See this if you're still stuck.

Reply 812

TheMoon

11

Original post by anujsr

If you have the edexcel textbook it is one of the proofs in topic 6

Oh is it? I have the edexcel textbook but I can't find it in there, but it's probably there somewhere, thanks!

Original post by kingaaran

Yeah, there's a range of alternative methods listed every year - yours is one of them. If you do the proof correctly, then you will get full marks

Thanks for the assurance! I assumed that the methods listed are the only ones accepted but that's good if they'll accept the way I do it as long as it's done right.

Reply 813

Zacken

22

Original post by TheMoon

Thanks for the assurance! I assumed that the methods listed are the only ones accepted but that's good if they'll accept the way I do it as long as it's done right.

This is true for any question. Also remember that examiners get a more detailed copy of the markscheme than the one you see.

Reply 814

Coreling

7

Can anyone explain where the 18p^2 goes in this question? seems to disappear? From the June15 paper question 8 (a).

Original post by indecisiveness

Hi can someone explain how matrix rotation work for multiples of 45°? Thank youu

If you work from the unit vectors.
The i vector if you rotate it 135 degrees for example anticlockwise will end up going around until it reaches the (+x, -y) quadrant. The x coordinate of that will be -cos45 and the y coordinate sin45.

The j vector will rotate until it reaches the (-x, -y) quadrant. The x coordinate will be -cos45 and the y coordinate will be -sin45.

So (1,0) will change to (-sin45, cos45) and (0,1) will change to (-sin45, -cos45).
Alternatively you can use the formula sheet. :biggrin:

Reply 816

TheMoon

11

Original post by Zacken

This is true for any question. Also remember that examiners get a more detailed copy of the markscheme than the one you see.

Oh that's good, I thought that mark scheme was the one they use since it has a lot of notes, but that's definitely good if they get an even more detailed one.

Original post by tazza ma razza

ahhhh good to see my go to method for divsivion proofs - get it right every single time espicially if the question comes at the end of the paper! Unless of course it is like a question 2 or 3 proof where you can use the f(k+1) -f(k) method

Yeah it's brilliant! Never fails, it makes everything work out very easily even on the harder questions. Glad that I'm not the only one using it.

Reply 817

Windowswind123

2

Original post by Coreling

Can anyone explain where the 18p^2 goes in this question? seems to disappear? From the June15 paper question 8 (a).

Take nine out as a factor: 9(p^4 + 2p^2 + 1)
Let x=p^2
9(x^2+2x+1)
Factorise:
9(x+1)^2
Square root:
3(x+1)
Resubstitute:
3(p^2+1)

Reply 818

iMacJack

16

Original post by Zacken

Normal divisibility (by 3). Consider

f(k+1) - f(k)

. See this if you're still stuck.

Aha got ya.

Also, you know in the F1 Jan 16 paper you sit, you see the question about the coordinates of where the normal intersects the parabola again (or something along those lines) and you have a dirty quadratic with like p^3 and p^4's and what not - how on earth do you use the quadratic formula successfully to work out the coordinates?? I'm so baffled!

https://gyazo.com/98e0758d1498ec2a5addcd7bfc1f15ee

Part B is what I'm on about