OCR (not MEI) C2 - Wednesday 20th May 2015

What do you think you got?

Could anyone tell me what the trapezium question was?

If anyone is looking for an unofficial markscheme, I'll post it again:

Xsanda's solutions:
1i) common ratio:[1]
r=-2
1ii) 11th term: [2]
ar¹⁰ = 3072
1iii) sum to 20: [2]
Sum to 20 = -1048575

2i) trapezium rule: [4]
21.4
2ii) improvement: [1]
more/narrower strips

3i) shaded area: [4]
32.1
3ii) perimeter: [5]
22.7

4i) Binomial expansion: [4]
64+192ax+240a²x²+…
4ii) Find a: [5]
a=2/3

5) Double antidifferential: [7]
y=4x^(3/2)-7x-3

6i) Factorise: [4]
(x-2)(x+5)(x-3)
6ii) Integrate: [4]
256
6iii) Problem with integral: [2]
negative section of integration counts negatively

7i) u₂₀: [2]
62
7ii) Σ 10 to 20 show that: [3]
517
7iii) Σ N to 2N: [6]
N=24

8a) log 2^(n-3) = 18000: [4]
n=17.1
8b) simultaneous logs: [5]
x=32, y=8

9ia) Next solution of cos: [1]
6π-α
9ib) Solution with negative: [2]
3π-a
9ii) Draw graph: [2]
graph of sin, half height
9iii) Solve graphs: [4]
3.32, 12.7

The answer was 21.4 and then to use more/ narrower sections

this adds up to 74, anyone know which question has 2 extra marks?

this adds up to 74, anyone know which question has 2 extra marks?

this adds up to 74, anyone know which question has 2 extra marks?

If you calculate it you get 256 and this is incorrect as it should be higher than this;
some area gets subtracted as a small part of the area is below the x axis

I got something really close to 256 - I think I integrated between 2 and -5, which gave me a positive value as it's above the x-axis. Then I integrated between 3 and 2, which gave me a negative value as it's below the x-axis, but I ditched the minus and added it on to the total. Got something like 258.75 or something. Does that sound alright?

Anyone get x=32 for the simultaneous equations🙏🏼 and wtf even was question 9😭😭😭 overall I didn't find it too bad, just messed up on Q9 and finding out what N was in the summutations question😓

This is how I did it


La vie? C'est la vie.

Can someone draw the sin1/3 x graph pls ????? X

just looked at the rough mark scheme I'm pretty sure i lost around 9/10 marks do u think that could be an a?