You are Here: Home >< Maths

# Edexcel C3 June 2016 - Unofficial Mark Scheme watch

1. (Original post by GrandMasti)
Hopefully you don't lose a mark for leaving it as 1/2ln(25/4)
hope not haha I didn't realise you could have square rooted it at the time. But hopefully still get the mark maybe

(Original post by Lyle10142)
Any one remember the boundaries for question 8 as pi/4<X<pi/2 or something like that
everyones saying differently, some people think it was -pi < X < pi otheres think -pi/2 < X pi/2 and what you said.
2. (Original post by veldt127)
I'm not 100% sure on all of these, but I think most are correct.

Question 1
Spoiler:
Show
A. -5, 6
B. 6
Question 2
Spoiler:
Show
A. (20-4x^2)/(x^2+5)^2
B. >sqrt(5), <-sqrt(5)
Question 3
Spoiler:
Show
A. R= sqrt(5)
a= 26.57°
B. 33.0°, 273.9°
C. 86.1°
Question 4
Spoiler:
Show
Ai. 21
ii. ln(2.5)
iii. 25
B. Show that question
C. 1.4368, 1.4373
D. Show the root was in [1.4365, 1.4375]
Question 5
Spoiler:
Show
i. 0.9463
ii. 0.5cosec(4Y)
Question 6
Spoiler:
Show
A. A=3, B=4
B. Normal eqn. -0.5x + 17.5
Question 7
Spoiler:
Show
A. graph of arcsin, sort of a rotated S shape. Went through (0,0), (-1,-pi/2), (1,pi/2)
B. -1-0.5sqrt(3)
Question 8
Spoiler:
Show
A. Trig proof
B. -2.848, -1.277, 0.294, 1.865
Question 9
Spoiler:
Show
A. 6.740 - dose after 4 hours
B. show that dose equalled a value after 7 hours
C. 5ln(2 + 2e^-1)
A = 5, B = 2
PDF with working for 1-4 and 9 : http://www.thestudentroom.co.uk/atta...5&d=1466508775
I don't think question 5ii is correct. I think it's -0.5 because we had to differentiate cosx which mean that the term became negative. So I think it should be -0.5 instead of 0.5
3. (Original post by Aethrell)
That's what I got, no idea if you need both or if either would do.

Can't even remember the question
Thats what i got too, why would it be 0.9somethin?
4. (Original post by jshep000)
No if I remember the gradient was 2 when you put x=3 into dy/dx. Then it was asking for the normal so m = -1/2.

2y-32 = -1 (x-3)
2y-32=-x+3
x+2y-35 = 0 for the full 5 marks.
Oh nooooooo, I think I had a + instead of a - using the quotient rule... That'll be what 2 marks gone?
5. (Original post by Matte0)
I got A=-5 for the last question. Did I do something wrong or is there a typo?
I think u made the mistake when the "e" bit of the term was flipped. Maybe u didn't change the sign of the power after flipping it.
6. (Original post by chandlerr)
Oh nooooooo, I think I had a + instead of a - using the quotient rule... That'll be what 2 marks gone?
Yeah it was a 5 mark question, so you'll probably lose the final answer and one method mark maybe I'm not too sure. 2 or 3 maybe
I think u made the mistake when the "e" bit of the term was flipped. Maybe u didn't change the sign of the power after flipping it.
Ok thanks.
8. (Original post by emmashaw)
does anybody know how many marks question 9 was worth? i didn't see it so i missed the entire question
8 marks

Hopefully you still did well
9. (Original post by Assfjeed)
F********K.

Omg for 3.a. I got r=root(5) , and I got a=63.43...

I got the value of 'a' wrong and I used this value for the rest of my question!!!!!
How many marks would I lose if I got the method correct?
2 method max (if examiners can be bothered) since rest are accuracy marks
10. (Original post by cun)
Thats what i got too, why would it be 0.9somethin?
out of range. i got it wrong too. how many marks do you think we'll lose?
11. for the last question i got a=-5 and b=0.5 can someone tell me why?
I don't think question 5ii is correct. I think it's -0.5 because we had to differentiate cosx which mean that the term became negative. So I think it should be -0.5 instead of 0.5
It was the differential of sin^2(2x) I believe.
13. Q4B? Smallest value of theta?
14. Your welcome how did everyone find the exam today question 8 was particularly troublesome but the rest of the questions weren't too bad.
Attached Images

15. (Original post by chandlerr)
I got a gradient of the tangent as 10, so the gradient of the normal was -1/10, I think I got y-16=-1/10(x-3) and then simplified, I don't think you need to simplify it though as it didn't say in the question so leaving it in that form would be fine I guess
I got y as 16, remember that
16. (Original post by jbaten)
Your welcome how did everyone find the exam today question 8 was particularly troublesome but the rest of the questions weren't too bad.
Thanks, looks like it will have to be ln(5/2) not 0.5ln(25/4).

Doing worked solutions for 5-8 now
17. How many marks will be lost for getting the wrong value of the turning point? My method was otherwise correct
18. Q 3C apart from 86 I also got 327
did the question ask for domain of theta
19. (Original post by GrandMasti)
Hopefully you don't lose a mark for leaving it as 1/2ln(25/4)
Sorry to be the ****; but 99% sure in previous mark schemes whenever its asked for simplified forms, you need to simplify it as much as possible if not it'll deduct the A1 mark
20. (Original post by Patrick Gekko)
ok guys so i have a question about how many marks i'd get for question 6, where you had to find the values of A and B and then the eqn of the normal.

I tried part a properly a few times and could not get it for some reason, but then i looked at part b. i noticed if you differentiated the given function then you'd get rid of A. I put the original eqn into my calculator to find the gradient of the tangent at the point (2), then obviously found the normal gradient and equation.
Through this i could create and equation for B, so work out that B=4. then just sub this into the original eqn to find A=3. i just wrote 'comparing coefficients gives...' for the 'working' (though I didn't cross anything out, but i'm pretty sure it was all wrong anyway)

obviously this is a very dodgy method, how many marks am I looking at? thanks.
I'd give you full marks if it was up to me. I'll be honest, though, you might not get very many marks.

The second part will have an alternate method in the mark scheme for differentiating the fraction rather than the simplified quadratic. However, if you didn't do this algebraically, 'cheating' by subbing it into your calculator, you might not get any marks for it. The examiner might be a bit mystified as to how you got the normal equation, but you should get method marks for the last bit of part (b). As for the first part, it depends exactly what you wrote - you didn't cross anything out, and the paper is marked from 0 upwards rather than from 75 and penalising mistakes, so you have a good chance of getting method marks if anything you wrote resembled long division or factorisation by sight. You did get the correct answer, and because factorisation by sight is a valid method (and there are some genius mathematicians who could do the full question in their heads), it is possible that the correct answer will score the A marks without working.

Part (a) was worth 4 marks and part (b) was worth 5 marks. I would say your answer could get anywhere between 2 and 6, depending on how the mark scheme is written and which examiner marks your paper. I know that's already probably an unhelpfully large range, and on top of that I have to add the disclaimer that I'm not an examiner or even a teacher, but please don't stress out about it because there's nothing you can do to change it now.

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: November 8, 2016
Today on TSR

### Buying condoms for the first time - help!

Discussions on TSR

• Latest
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
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