Competition - post a photo you've taken of nature >>

Edexcel FP2 Official 2016 Exam Thread - 8th June 2016

Scroll to see replies

Oh yeah, you still have your GCSEs to worry about. How are they going?

Everyone is moaning about question 4, where you had to integrate e^2x sin x IIRC

Easy to do if you remember sin x = (e^ix - e^-ix)/(2i), but otherwise just IBP twice

I think I lost at least one mark on the last question, I got the exact answer correct I think, but I added it up wrong (forgot to add the arccos 3/4, so my final answer was wrong). STEP has made me forget how to use a calculator...

I did it a different way, saves a long time:

Original post by Insight314

ImageUploadedByStudent Room1465405839.248518.jpg

Prove me wrong.Pro-tip: You can't.Posted from TSR Mobile

Damn, I just found out about this exponential form of sine. You are too good with complex numbers! :biggrin:

I bet you are gonna have some fun time in the STEP III exam if Siklos floods it with complex numbers once again, haha. I am trying to work on my STEP complex numbers/vectors/mech in the next two weeks. :smile:

GCSEs are going pretty well, thanks for asking, but probably failed GCSE Geography due to not being in classes since January and so not knowing any of the case studies lol. The other one I had today, Computer Science, went pretty well though.

Yeah, that last question was so ****ing annoying, wasn't it? It was really fiddly, mainly due to the fact they couldn't just use pythagorean triplets, so you had to carry that arccos with your integral. I kind of avoided that, though, by letting it equal to a variable and then just using triangle to find values for sin and cos, using sin 2\theta identity and then writing down the answer. I think I got full marks, so I am pretty happy with my performance. I feel like my A* in FM is banked right now, but I still have Physics and (especially) STEP to worry about! :biggrin:

Good luck to both of us with our offers (especially with STEP II next week), and well done with your FP2 performance today, even though you made a small mistake at the end, I feel like that is still 100UMS. :smile:

Reply 2141

Wsswilliamoxley

Original post by Pixel_Green

Well according to me in the exam, 3^2 = 3 when you put it in front of an integral sign on 8b. Bye bye 3-5 marks there. Then countless dumb errors or lack of completion due to lack of time

Yeah that's what pressure does, relying on M2 or D2 now🙏

Reply 2142

Smeagul

I know the roots were correct but this is what a did for the sketch of the roots on an arg and diagram. Is this detailed enough for both marks?

Reply 2143

fpmaniac

Original post by kelvin1338

Very likely, but not certainly. I know people who've been rejected getting 1 mark off A* in further maths.

What is likely?

Reply 2144

PhysicsIP2016

Original post by Pixel_Green

In future you can write y = arcos(3/4) and write y instead of arcos(3/4) all the time to save time.

The same applies to DeMoivre's etc, writing y=cos(theta) or y=sin(theta)

Ooh that's a good idea, thank you! :smile:

Reply 2145

Pixel_Green

I've got worked solutions written for all but Q5-7, well I have one of 5 to 7 done but dont know which one it is. So if you want my take on the paper I need to know what the questions were lmao

Reply 2146

JoshC98

Has there been an unofficial mark scheme made?

Reply 2147

Pixel_Green

Original post by JoshC98

Has there been an unofficial mark scheme made?

As far as I'm aware, no.

I'm nearly finished with some worked solutions, can you remember something...

For the tan(x) expansion up to term (x-(pi/4))^3, in part 'b', it asks you to use the expansion to get an approximate for tan(theta), I can't remember what theta was.

Also for another question regarding DeMoivre's, in part 'b' you have to show the integral of (sin^5(theta) +something?) = ~53/400ish. (I can't recall precisely, not sure if anyone else can help with that).

Otherwise wait till tomorrow after the paper is released on Edexcel site and people get it done

Reply 2148

JoshC98

Original post by Pixel_Green

I think for the de Moivre's part (b) it was 53/480. Also, I feel like it may have been tan(pi/6)? Not at all confident in that though.

Reply 2149

EricPiphany

Original post by Pixel_Green

Was it

\dfrac{5 \pi }{12}

?

Argh, 5π/12.

(edited 7 years ago)

Reply 2150

Pixel_Green

Original post by EricPiphany

Was it

\dfrac{5 \pi }{12}

?

Argh, 5π/12.

I'm stuck between whether it was 5π/12 or 7π/12 now.

The DeMoivre's equaled 53/480 Im pretty sure, I just cant remember the integral

Reply 2151

js.int

Original post by Pixel_Green

I'm stuck between whether it was 5π/12 or 7π/12 now.

The DeMoivre's equaled 53/480 Im pretty sure, I just cant remember the integral

It was definitely 5π/12

Reply 2152

Pixel_Green

Original post by js.int

It was definitely 5π/12

Okay. Boss.
Any clue on intergral for DeMoivre's?

Reply 2153

kelvin1338

For the Argand diagram, I converted the solutions into a+bi form (in decimals to 3sf) then plotted it like a coordinate system. Even though I did not write on the diagram which corresponds to which (in the form of e), Do you guys think I should get 2 out of 2 for that? My solutions are definitely correct and they are plotted on the right spots.

(edited 7 years ago)

Reply 2154

Mattematics

Original post by Pixel_Green

Okay. Boss.
Any clue on intergral for DeMoivre's?

It's the integral of whatever (2isinx)^5 turns out to be between 0 and pi/3.

Reply 2155

Pixel_Green

Original post by kelvin1338

I think if your co-ordinates were accurate it may be fine, it didn't specify any particular way to sketch it. It's 1 mark for sure, probably 2, I'd go with yeah its worth 2 if they dont want each solution labelled on the diagram explicitly

Reply 2156

Pixel_Green

Original post by Mattematics

It's the integral of whatever (2isinx)^5 turns out to be between 0 and pi/3.

Are you sure it is (2sinx)^5 and not just (sinx)^5?

(2sinx)^5 gives an answer 32 times larger than expected, funnily enough 2^5 = 32.

Reply 2157

Pixel_Green

Here are my worked solutions to the FP2 paper, it would be good for someone to look through and double check the solutions. As this was recollected from memory (mine and others' :wink:

it may not be 100% accurate but should be close enough.

Q1:

Attachment not found

Q7 + Q8 will be in the post after this, can only have up to 10 attached files.

Edit: Please look at thumbnails as some links dont work, though the thumbnails do

(edited 7 years ago)

1465432607569-1054175603.jpg373.2KB

1465432556686-967689434.jpg316.2KB

14654325091121553773317.jpg355.6KB

1465432440181-231899861.jpg325.3KB

1465432327208-2094169325.jpg318.6KB

1465432269319-1250161023.jpg312.4KB

1465432144948-375552386.jpg328.3KB

1465432083008-345650018.jpg304.7KB

146543267207863688186.jpg338.5KB

Reply 2158

Maetras

Original post by Pixel_Green

Would you still get two marks for using different sf? I used 2sf for 0.26 and 3sf for 1.98 for some reason. I did however label each point.

Reply 2159

Pixel_Green

Here are my solutions for Q7+8

Attachment not found

Apologies if any qyestions are mis-numbered and for the poor layout.

I hope this is useful, I believe this is mostly correct, if not completely. Feel free to correct me. Some questions can be done in many other ways