OCR (not MEI) C1 - Wednesday 13th May 2015

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Yeah, in comparison, 2014 was more straightforward than this one as lot of of people tripped up. It's normally low 60s, high 50s.

I agree. I saw the last question and knew some people would get that wrong and there wasn't a question quite as challenging in last year's paper. I'm optimistic really :smile:

Reply 201

Parallex

Original post by ella_chloe

i thought the answer was the minus one ?

it was -1/48 lol

I got 1/3 y axis too

A few definite correct answers:
1) first question was 4(√ 3)+4
2) indices:
i) 5^8
ii) 5^(-1/4)
iii) 5^(9/2)
3) with two simultaneous equations, solutions were:
x=14/3, y=-13/3, and
x=2, y=1
4) The quadratic with unknown 'a', a=13
5) transformations:
i) 1/(x-2)^.... (Can't remember the denominator power - it was the '-2' that's important)
ii) the one with denominator '3x' was a stretch scale factor 1/3 parallel to the x-axis (in the x direction) OR parallel to the y axis (in the y axis) as both do the same transformation in this example.
X DIRECTION AND Y DIRECTION BOTH RIGHT!
6) with another quadratic curve question, with something like 2x^2-x-3=0;
The curve intercepted the x axis at -1 and 3/2, and the y axis at -3.
When it asked for the values of k, k<-25/8
7) with the curve y=x^(-1/3) and at the point x=-8, the gradient was -1/48
8) the circle question: centre (5,-2), radius 5.
The then triangle PQR later in that question had area 40.
Sorry if they aren't in their test order, and good luck everyone doing C2 tomorrow!

(edited 8 years ago)

Reply 204

Magnesium

Original post by ChoccyPhilly

I agree. I saw the last question and knew some people would get that wrong and there wasn't a question quite as challenging in last year's paper. I'm optimistic really :smile:

yeah haha. I managed to trip up on that one too. Maths are quite lenient with ecf right up until the A1 mark for the final answer so i'm sure it'll be fine :smile:

Original post by Parallex

it was -1/48 lol

Agreed. It's -1/48

Reply 205

sandpitturtle

Original post by Parallex

it was -1/48 lol

yeah i thought so ahah, i put minus and i cant afford to lose any more marks after crossing out the 40 in the last q

Reply 206

Numpers123

I got 25 for last one so annoyed. And had the right answer for k then crossed it out :frown:

Reply 207

AlfieH

Original post by Parallex

it was -1/48 lol

Nope because the substitution was -8 therefore -⅓x-8^-4/3=1/48

I put -1/48 though...

Reply 208

Parallex

debate: is this stretch parallel to x or y

I think both

Reply 209

Simonium1010

Original post by Numpers123

I got 25 for last one so annoyed. And had the right answer for k then crossed it out :frown:

As long as you didn't put a new answer, and the crossed out answer for k is legible, you'll get full marks for that.

Reply 210

Parallex

Original post by AlfieH

Nope because the substitution was -8 therefore -⅓x-8^-4/3=1/48

I put -1/48 though...

-1/48 is the answer man

(8)^{4/3}

and

(-8)^{4/3}

both equal 16

(edited 8 years ago)

Reply 211

Numpers123

I crossed it out and out a new answer ahhh

Reply 212

AlfieH

Original post by Parallex

-1/48 is the answer man

(8)^{4/3}

and

(-8)^{4/3}

both equal 16

Good!

Reply 213

Simonium1010

Original post by Parallex

debate: is this stretch parallel to x or y

I think both

With this curve, a stretch of scale factor 1/3 is identical in both directions

Reply 214

AstroNandos

I have a feeling I forgot to work out the y value for the simultaneous equations too...

:banghead:

Reply 215

lily9666768

this is just what i remember! could b wrong

1. 4√3 + 4

2. (i) SKETCH

(ii) -1/(x-2)

(iii) stretch parallel to x axis by scale factor 1/3

3. (i) 5^8

(ii) 5^-1/4

(iii)5^9/2

4. x= 27, x= -8

5. (i) AB length: 5

(ii) 3x - 4y - 29/2 = 0

6. x = 14/3 when y = -13/3
and x = 2 when y = 1

7. (i) -3x^2 -10x-3

(ii) -1/48

8. (i)SKETCH

i kinda forget the order of the questions here lol....
so i think:

(ii) x<-1 and x>3/2

(iii) k<-25/8

9. (i) A = 13

(ii) other stationary point: 1/3

i think there was more to question 9......?

10 (i) centre (5,-2)

(ii) show that

(iii) 40

correct me if I'm wrong lol!