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# AQA maths core 1, 13th May 2015 watch

1. Is there an edexcel unofficial mark scheme anywhere,
2. Can anyone remember the equations they gave for the surds? i remember getting 7-root5 instead of 7+root5
3. (Original post by sohail90)
Can anyone remember the equations they gave for the surds? i remember getting 7-root5 instead of 7+root5
The coordinates were something like (√3, 2√3) and (√5, 4√5) with the answer 7 + √15
4. (Original post by ell98)
For the circle question did it say to write the radius in the form n root something because I have just read that the equation was in the form (x-a)^2 + (y-b)^2 = d which would mean that the diameter was 50 so the radius would just be 25?

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d does not represent the diameter. It represents the radius squared. So the radius is the square root of 50 which can be simplified into the surd form of 5 root 2.
5. (Original post by -jordan-)
d does not represent the diameter. It represents the radius squared. So the radius is the square root of 50 which can be simplified into the surd form of 5 root 2.
Oh that's alright then haha

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6. What would a B likely to be?
7. (Original post by stabulo)
x^2(x-3) there is a repeating root at x = 0, and it passes through x = 3
so it touches x = 0 not goes through.
yeah realized afterwards i made such a stupid mistake(well worse than a mistake) i ignorantly drew a quadratic going through x=0 and x=3 felt like shooting myself.

you know for the question where you needed to find dV/dt, if you differentiated it wrong but did the next part of the question (find stationary and if max or min) (4Marker) would you get error carried forward marks?
8. (Original post by sohail90)
Can anyone remember the equations they gave for the surds? i remember getting 7-root5 instead of 7+root5
You got 2 pairs of coordinates, not an equation. And it should also be root15 not root 5 (comes from root3 multiplied by root5). Afraid I can't remember which numbers they gave though.

Edit: You may even be right with the 7-root15, as thats what I remember getting...
9. (Original post by starfish5577)
On the cylinder question who got 4 for the stationary point ?
Thats correct
10. do you still think you'd 3 out of 3 for the simultaneous part in q1 if you got the right answers for x and y but didn't put them into co-ordinate form?
11. On the integration question where you had to find the area of the shaded region, I did it all correctly except when working out the area of the trapezium I used the area of the triangle plus the area of the rectangle, and forgot to add the area of the rectangle, so I did 36- 108/5 instead of 54. How many marks do you think I'll lose for that? I have the area of the trapezium written down I just made a stupid mistake!
12. (Original post by ImLiterally12)
I ended up rushing the cylinder question in about 5 mins at the end, but somehow I got to the given answer. I worked out an equation for the surface area (Which i think was given as 49π?):

49π= πr^2 + h(2πr) where h is the height of the cylinder and 2πr if the circumference.

I then worked that through to make h the subject. For part b I worked out the volume to be V=2πr^2 x h and substituted in the equation for h from part a.

Hope that makes sense, I found the paper to be harder than most of the past papers I did so I think grade boundaries might be higher than usual.

Hope everyone gets the grade they wanted!

You mean Grade boundaries should be lower right?
13. (Original post by l1lvink)
You got 2 pairs of coordinates, not an equation. And it should also be root15 not root 5 (comes from root3 multiplied by root5). Afraid I can't remember which numbers they gave though.

Edit: You may even be right with the 7-root15, as thats what I remember getting...
It was definitely plus. The form was n + √15 not n + m√15 for example, where m would be -1. My previous coordinates, (√3, 2√3) and (√5, 4√5) give this answer too.
14. For the intergration one did anyone make the denominator over 15 instead of 5?
Would i still get a mark. it should still be the same answer right?

And aldo for the simultaneous equation i got fractions i was so confused because simultaneous equations are usually really simple for me and i was sure my answer wasn't right. so I did it again and did it really slowly and still got fractions Does anyone remember the two equations so i can try it again now?
15. (Original post by student0042)
The coordinates were something like (√3, 2√3) and (√5, 4√5) with the answer 7 + √15
Pretty sure it came to (-14 - 2root 15)/(-2) which becomes 7 + root 15
16. (Original post by rhoxc)
For the intergration one did anyone make the denominator over 15 instead of 5?
Would i still get a mark. it should still be the same answer right?

And aldo for the simultaneous equation i got fractions i was so confused because simultaneous equations are usually really simple for me and i was sure my answer wasn't right. so I did it again and did it really slowly and still got fractions Does anyone remember the two equations so i can try it again now?
I think I got 9 and -2
17. (Original post by RhyaCeri)
its 5x? i think, im not sure, pretty sure im gonna have nightmares about that cylinder question tonight though
Well this cylinder question basically ruined the exam for me. Spent about 20 mins wondering why I couldn't do it. Then realised 2 mins before the end that the surface area = 48pi and not 48.

Drew the cubic sketch as quadratic. (**** me)

Wrote the integral as 108/5. Didn't want to mess with fractions so I wrote it as 21+3/8 pulling the /8 out of my ass. (**** me again)

Somehow got -31/3 and some other fraction for the simultaneous, although I had the right equation, from what I see posted here.

Panicked on the last quadratic because I couldn't see the factors to -144 and tried to brute force the quadratic formula, but of course in my panic made numerous addition and multiplication errors.

Well, all I have to do now is get 100% on C2 and S1 and I'm fine. Easy, peasy........
18. 105/8
19. (Original post by -jordan-)
Pretty sure it came to (-14 - 2root 15)/(-2) which becomes 7 + root 15
It would be minus if you did y1 - y2/ x... I did it the other way round, which kept it positive anyway.
20. (Original post by Rk2k14)
What would a B likely to be?
Last 3 years it has been 55, 59, 55. So i'd say between 55 and 60. May be closer to 55 mark this year due to that lovely cylinder question.

Spoiler:
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I messed that up on the simple part

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