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# C1 13/05/2015 Answer discussion watch

1. Finished the C1 exam a few hours ago. It was difficult in my opinion, and I will never get near to Jess' salary because of it. I am going to post some of the answers I got. You DO NOT have to assume that these are correct, they may be wrong so please do not panic if you answered differently. Feel free to post your own answers and share, I know it can be tempting to see if you are correct.
I cannot remember what every question was about but I think that I got the following answers:
Question1
a. 20
b. 3 + root 10
2. (I am not sure if this was question 2)
i. (x)(3+2x)(3-2x)
iii. Negative cubic, going though (-3/2,0) , (0,0) , and (3/2,0)
7.
a. y^2
b. x=-3,x=0
9.
a. Was a show that
b. £557,500
10.
a. can't remember the whole expression but I think that I got c=2.
b. x=3/2 <---tough one, really tough

for the question with recurrency formulas, I can't remember the question number but I think that I got the following answers:
a.
i. 4 ?
ii. 80 (20x4=80)
b.
i.3k,4k basically, Un=nk
ii.k=11 (165/15=11)
For the question with inequalities and p:
a. Show that question.
2. Heya, I'm going to put this in the Maths forum for you as you should get more responses there.

You should also check out the forum to see if there's any other threads there which might be helpful to you!

http://www.thestudentroom.co.uk/forumdisplay.php?f=38
3. (Original post by GabrielSmith1998)
Finished the C1 exam a few hours ago. It was difficult in my opinion, and I will never get near to Jess' salary because of it. I am going to post some of the answers I got. You DO NOT have to assume that these are correct, they may be wrong so please do not panic if you answered differently. Feel free to post your own answers and share, I know it can be tempting to see if you are correct.
I cannot remember what every question was about but I think that I got the following answers:
Question1
a. 20
b. 3 + root 10
2. (I am not sure if this was question 2)
i. (x)(3+2x)(3-2x)
iii. Negative cubic, going though (-3/2,0) , (0,0) , and (3/2,0)
7.
a. y^2
b. x=-3,x=0
9.
a. Was a show that
b. £557,500
10.
a. can't remember the whole expression but I think that I got c=2.
b. x=3/2 <---tough one, really tough

for the question with recurrency formulas, I can't remember the question number but I think that I got the following answers:
a.
i. 4 ?
ii. 80 (20x4=80)
b.
i.3k,4k basically, Un=nk
ii.k=11 (165/15=11)

For the question with inequalities and p:
a. Show that question.
Pretty sure 1b was 3 plus root 5
4. i think question 9 a was not a show thing, i got the answer k=11 (the year)
Question 1 b was 3+root 5
5. Awh wow you seemed have to done really well I got similar to you but made stupid mistakes now i come to think of your answers but i didnt don the last qs..ran out time but i managed to now awh so annoyed....

Just really praying grade boundaries are low...know ive missed like 11 marks for sure..
6. How did eveyone write 4^x in terms of y where y=2^x ?
7. (Original post by neo11)
How did eveyone write 4^x in terms of y where y=2^x ?
as y2 (y sqaured)

But made such a stupid mistake with the factoring completely lost my mind
8. (Original post by neo11)
How did eveyone write 4^x in terms of y where y=2^x ?

Well y= 2^x

to make 4^x

Then square both sides of y=2^x

so that it= y^2= (2^2)^x

That's what I did... not sure if steps are right but yeah it was y^2
9. (Original post by JhusJane)
as y2 (y sqaured)

But made such a stupid mistake with the factoring completely lost my mind
For the factorising didn't you have to just substitute the 4 with y^2?

and y with the 2? so that it is a normal quadratic?
http://www.thestudentroom.co.uk/show....php?t=3322783

So far I marked my self and I predicted I am guaranteed at least a C, more likely a B.
11. I couldn't do the discriminant question. on part B I completed the square.
12. Hi, do know for the graph question I drew my line from bottom instead of top but got the same coordinates, how many marks will I get out of 3? Also for the 7b the power question I left it to y=1/8 and y=1, I didn't solve it, how many marks will I get???
13. you know for the 9x+4x^3 graph question, I wrote the co-ordiantes as 3+2x, 0 0,0 and 3-2x, 0 , Idek why i did that, in hindsight, but how many marks would i lose for that?
14. (Original post by zahraa.al-obaidi)
I couldn't do the discriminant question. on part B I completed the square.
I did that too, but then I didnt cancel down sqrt(8.....
F****!!!
15. (Original post by shahkr)
Hi, do know for the graph question I drew my line from bottom instead of top but got the same coordinates, how many marks will I get out of 3? Also for the 7b the power question I left it to y=1/8 and y=1, I didn't solve it, how many marks will I get???
1 mark for the coordinates
0 for the curve
I think it's one mark for the (0,0) point

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16. Pretty sure only mistake I did was to forget to divide the 4root2 part of the inequality by 2... Stipid... I got 3 + root10 for 1b as well. Everything else from OP seems right Good luck on C2 next week guys, and good luck for those who are taking FP1 tomorrow, I will be doing it too And yeah, I hate Jess' job too.
17. Pretty sure 1b gave something along the lines of 'write your answer in the form a + b√10'
18. (Original post by snowflake97)
Pretty sure 1b gave something along the lines of 'write your answer in the form a + b√10'
Yup, and that was a=3 b=sqrt(10)
19. (Original post by Yousf)
Pretty sure 1b was 3 plus root 5
I

I think that you are mistaken.
I am guessing that you accidentally made 2root10 root5 by accidentally dividing both the 2 and 10 by 2. i think that it should have been root10 (with the +3)
20. (Original post by JhusJane)
Awh wow you seemed have to done really well I got similar to you but made stupid mistakes now i come to think of your answers but i didnt don the last qs..ran out time but i managed to now awh so annoyed....

Just really praying grade boundaries are low...know ive missed like 11 marks for sure..
unfortunately, I think that the grade boundaries are being raised unconditionally
I am guessing that 65 will be an A (stupidly high if you ask me) and that 100UMS will be 75/75.

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