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C1 Maths AS aqa 2016 (unofficial mark scheme new)

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Original post by Alexcor
My brain stopped working on question 7 😠😢😠😢 because i made a mistake somewhere so i spent about 20 minutes on it(mainly staring blankly...and crying inside 😥) so I'm pretty sure it was as follows:

a) answer was y=-32x - 40

b)find x coordinate of axis intersect (of Q i think?)

c) the 5 marker integration question: 81/4

d) shaded area (I believe you used the x coordinate you found of on part b to find the area of the triangle) .: area= 45/4

The point is, i somehow got y=-32x - 26 for part a so i got part b and c wrong too. Anybody know how many marks was it for QUESTION 7 PART A, B & D?!?

Thank you 😄

a) was like 5 marks i think, (cos you had to find the gradient and the equation no?) and d) was only 3. But not to worry even if you made a mistake you should get some method marks e.g. for finding gradient etc.. and might get some follow through marks in part d) . Im sorry to hear about your issue with question 7, i think the grade boundaries will be a bit lower than usual and also a lot of people lost many marks on this question, including myself. Good luck though :smile:
Original post by timtjtim
Mark Scheme with some workings etc.


Nice work and very useful! Are you planning on adding allocated marks to the mark scheme though? I feel a lot of people will be looking at this to see where they gained/ lost marks to get a rough estimate of a grade. Anyways not a big deal :smile:
Reply 262
How many mark do you think I will lose for not simplifying final answers/ simplifying wrong??

Thanks
Reply 263
U guys think the grade boundary will low!!! I don't think so. overall, I think I did alright, except few parts of Qs. I found the paper challenging but not too hard though. I hope the grade boundry will be low as u guys say.
Reply 264
Can some1 explain 6d. I got my signs wrong.
It's root65, you need to work out the length of AC. Which is root65 and that's the radius. I got that wrong too so I went to my teacher and described the question fully and he said no that's not the way to do it. A lot of people got root34 as the radius though
Reply 266
For question 8 I'm pretty sure they gave DY over dx as 54 + 27x - 6x^2 then you had to find the second derivative and from that prove x = -1.5 had a minimum. This right?
Original post by Azi16
Lol!!! According to ur answers I prob failed this exam. I don't know how u guys managed to get x=-1+_ root5. Because I got root-5, I know that is wrong.


well you cant root a minus number so your obviously wrong so you made some amateur mistake there my g.
Can anyone remember what they asking for question 1, I think I got the gradient wrong for the first part:frown: will this affect the rest of the answer on this question? Thanks
I think 7)a) asked you to find the tangent at x=-2 on the curve and b) asked you to find the intersection with x axis of this tangent
I'm pretty sure that 7a) asked you to find the tangent to the curve at the point (-2,24) and 7b) asked you to find the x-intercept of this tangent which was -5/4
Reply 271
Original post by Konanabanana
well you cant root a minus number so your obviously wrong so you made some amateur mistake there my g.


As I said I know I got it wrong, but don't know how to get the answer.
well done

Original post by money-for-all
Love you bruv, i love people who make mark schemes, i imagine them as snails working away slowly on their computer, for hours on end.

You are mark scheme champion
Original post by beanigger
Unoffical Mark scheme for C1 AQA 2016

It would help if you could link answers to questions as i cant remember them :smile:

Questions:

1) a)Asked to work out gradient of a tangent, m= - 5/3 [2]
b)Asked to find co-ordinates of B B( - 3,4) [3]
c)Asked to find K K= - 30 [2]

2) a) simplify (3√5)^2 = 45 [1]
b) i cant remember the question but the answer was 75 - 32√5 [4]

3) a) y=(x-7/2)^2 - 41/4
b) min value = -41/4 [1]
c) Translation of (1/2 , 41/4)

4) a) show that (x+3) was a factor of x^3 - 5x^2 -8x + 48, p(-3) = 0, (x+3) is a factor of p(x).
b) three linear factors of p(x) = (x+3)(x-4)(x-4)
c) find remainder when p(x) was divided by (x+2) R=20
d) Factorise p(x) using (x+2) R = (x-2)(x^2-3x-14) + 20 [3]

5) a) asked to find equation of circle (x-5)^2+(y+3)^2=65 (note 65 = r^2) [3]
b) asked to find co-ordinates of B (AB is diameter) B ( 12, -7) [2]
c) asked to find equation of tangent at A 7x-4y+18=0 [5]
d) asked to find length of CT = 9 [2]

6) a) y=-32x-40
b)Q(-5/4) [1]
c) upside down positive graph passing through y axis at 8 [2]
d) x = -1±√5

7) a)
b)
c) definite integral = = 81 /4 [5]
d) area of shaded region = = 45/4 [3]


8) a) d^2y/dx^2= - 2x - 9x^2 [2]
b) verify that P was a minimum point sub x co-ordinate of P into dy/dx (given in the question) to prove it was a stationary point, then sub in x-coord of p into d^2y/dx^2 to get +45, d^2y/dx^2>0 therefore minimum point [4]
c) show that y is decreasing, so make your dy/dx<0 and rearrange to get into the form they wanted (note when you multiply by -1 the inequality sign flips)
d) cant remember anything except the answers were k>6 and k<-3/2

Answers that need a question to be assigned to
- k=4 and k=20


The last question was
solve the inequality 2x^2 -9x -18 >0
It was a four mark question.
Original post by Cassette
No, unfortunately you are expected to give things in the simplest form.

Does anyone remember how much of Q1 would be screwed up by giving the wrong gradient for 1a? I think every other answer I gave on the paper was correct, but I'm genuinely panicking about this one. I don't remember even doing Q1, which says it all really...


From what I remember, 1a was 2 marks - so you won't have lost many at all. :smile:
Reply 275
Original post by beanigger
Unoffical Mark scheme for C1 AQA 2016

It would help if you could link answers to questions as i cant remember them :smile:

Questions:

1) a)Asked to work out gradient of a tangent, m= - 5/3 [2]
b)Asked to find co-ordinates of B B( - 3,4) [3]
c)Asked to find K K= - 30 [2]

2) a) simplify (3√5)^2 = 45 [1]
b) i cant remember the question but the answer was 75 - 32√5 [4]

3) a) y=(x-7/2)^2 - 41/4
b) min value = -41/4 [1]
c) Translation of (1/2 , 41/4)

4) a) show that (x+3) was a factor of x^3 - 5x^2 -8x + 48, p(-3) = 0, (x+3) is a factor of p(x).
b) three linear factors of p(x) = (x+3)(x-4)(x-4)
c) find remainder when p(x) was divided by (x+2) R=20
d) Factorise p(x) using (x+2) R = (x-2)(x^2-3x-14) + 20 [3]

5) a) asked to find equation of circle (x-5)^2+(y+3)^2=65 (note 65 = r^2) [3]
b) asked to find co-ordinates of B (AB is diameter) B ( 12, -7) [2]
c) asked to find equation of tangent at A 7x-4y+18=0 [5]
d) asked to find length of CT = 9 [2]

6) a) y=-32x-40
b)Q(-5/4) [1]
c) upside down positive graph passing through y axis at 8 [2]
d) x = -1±√5

7) a)
b)
c) definite integral = = 81 /4 [5]
d) area of shaded region = = 45/4 [3]


8) a) d^2y/dx^2= - 2x - 9x^2 [2]
b) verify that P was a minimum point sub x co-ordinate of P into dy/dx (given in the question) to prove it was a stationary point, then sub in x-coord of p into d^2y/dx^2 to get +45, d^2y/dx^2>0 therefore minimum point [4]
c) show that y is decreasing, so make your dy/dx<0 and rearrange to get into the form they wanted (note when you multiply by -1 the inequality sign flips)
d) cant remember anything except the answers were k>6 and k<-3/2

Answers that need a question to be assigned to
- k=4 and k=20


Q(-5/4) must've been in question 7 because we made the triangle with Q (hence the -5/4 in answer for 7d)
Also, what mark do you think we'll need for 100ums? The only part I missed was subbing x-coord of P into dy/dx in 8b, I only subbed it into d^2y/dx^2 and wrote statement about 45>0 therefore minimum. Do you think I'll still get 100ums since quite a few people weren't too happy with this paper?
Reply 276
Original post by Rager6amer
a) was like 5 marks i think, (cos you had to find the gradient and the equation no?) and d) was only 3. But not to worry even if you made a mistake you should get some method marks e.g. for finding gradient etc.. and might get some follow through marks in part d) . Im sorry to hear about your issue with question 7, i think the grade boundaries will be a bit lower than usual and also a lot of people lost many marks on this question, including myself. Good luck though :smile:


5 marks ? 😯
😉thank you, and as you said, hopefully we pick up some method marks. Good luck to you too on C2
I know the number of marks for each question. I also know some questions. Let me know what question you want.

Marks:
q1) 6 mark total
q2) 5 mark total
q3) 6 mark total
q4) 10 mark total
q5) 13 mark total
q6) 8 mark total
q7)14 mark total
q8) 12 mark total
Original post by Azi16
As I said I know I got it wrong, but don't know how to get the answer.


you had i think -2(x+1)^2+10 = 0
bring 10 to other side and divide by -2 then square root both sides and move 1 to the other side. that gives x=-1 /-root 5

:smile:
(edited 7 years ago)
Reply 279
Original post by chocolatecocoyum
I know the number of marks for each question. I also know some questions. Let me know what question you want.

Marks:
q1) 6 mark total
q2) 5 mark total
q3) 6 mark total
q4) 10 mark total
q5) 13 mark total
q6) 8 mark total
q7)14 mark total
q8) 12 mark total


74 ??? 😁😜

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