Mr M's OCR (not OCR MEI) Further Pure 1 Answers May 2017

Mr M's OCR (not OCR MEI) Further Pure 1 answers May 2017

1.

\displaystyle \frac{n(n+5)(n-5)}{3}

(5 marks)

2.

\pm (3\sqrt{5} - i \sqrt{2})

(5 marks)

3. (i)

\begin{pmatrix} 6 & 28 \\-14 & 7a-1 \end{pmatrix}

(2 marks)

(ii)

\begin{pmatrix} 1 & 3a+28 \\-9 & 5a+4 \end{pmatrix}

(3 marks)

4. Proof (5 marks)

5. (i) Shear with x axis invariant taking (0, 1) to (5, 1) (3 marks)

(ii)

\begin{pmatrix} 1 & 0 \\0 & 4 \end{pmatrix}

(2 marks)

(iii)

\begin{pmatrix} 1 & 5 \\0 & 4 \end{pmatrix}

(2 marks)

(iv) 4 (2 marks)

6. (i) Sketch (3 marks)

(ii)

\sqrt{18}

and

\frac{7\pi}{20}

(5 marks)

(iii) Perpendicular bisector of line segment joining

z_1

and

z_2

(2 marks)

7 (i) Show (1 mark)

(ii) 0.629 (5 marks)

(iii)

\frac{71}{105}

(1 mark)

8. a = -24, b = 45, c = -52 (7 marks)

9 (i) a = 2 (5 marks)

(ii) Any value other than a = 2 (1 mark)

(iii) p = -1 (3 marks)

10 (i) Show (4 marks)

(ii)

b=\pm \frac{a\sqrt{3}}{3}

(6 marks)

Thanks to Mr K and Mr H for their work on this.

(edited 6 years ago)

Scroll to see replies

Reply 1

James2301

I think Question 8 and 9 (iii) are incorrect. I think that 8 should be a=-24, b=45, c=-52 and 9 (iii) should be -1.

Also on Question 7 (i) and (ii) I got those answers, but I don't believe I did it with the intended method. I formed two simultaneous equations to find Z1 and Z2, then did Z1 - Z2 and found a complex number, I then typed the values into my Calculator and came out with those exact values. Will I still get the marks for this or will I lose some?

Finally, how would you compare the difficulty of this paper to previous years?

(edited 6 years ago)

Reply 2

Ucalyptas

For q8, I don't think you need to divide through by 4.

a = -24
b= 45
c = -52

but thanks!!

Reply 3

Mr M

Study Forum Helper

Original post by James2301

I think Question 8 and 9 (iii) are incorrect. I think that 8 should be a=-24, b=45, c=-52 and 9 (iii) should be -1.

Sorry fixed. Inability to read question and add.

Reply 4

Ucalyptas

Mr M,

What do you think the grade boundaries will be like? Some say that they found it very hard compared to previous years, and some thought it was easy.

Do you think about 68/72 for 100 UMS is probable?

Thanks again

Reply 5

britishtf2

Original post by shreys

Dear Mr M,

Thanks for this again.

Just a few questions:

1.On the Argand diagram drawing one I drew the correct angles for the first two (z1 and z2), however didn't include much of a scale. How many marks would I drop?

2. On the question for finding p, I made a simple arithmetic mistake and got p=-2, not p=-1. How many would I lose for this?

3. On the final question, I made a small mistake and got close to the answer, but not the actual answer. I got most of the working right, however and accidentally only put one b value, not plus or minus. How many marks would I lose for this?

1. Depends what you mean by "much of a scale". If you were to lose anything, I would say 1.

2. Depends where the error was; an error at the end would lose you 1 mark, earlier on it could lose you more.

3. I don't see why you would lose more than 1 mark for missing +/- when it is needed.

Reply 6

James2301

Original post by Mr M

Sorry fixed. Inability to read question and add.

On Question 7 (i) and (ii) I got those answers, but I don't believe I did it with the intended method. I formed two simultaneous equations to find Z1 and Z2, then did Z1 - Z2 and found a complex number, I then typed the values into my Calculator and came out with those exact values. Will I still get the marks for this or will I lose some?

Also how would you compare the difficulty of this paper to previous years?

Reply 7

cfang99

@Mr M do you think the grade boundaries will be lower this year 9say compared to the 2016 one), or did you find this paper fairly standard

Reply 8

Mr M

Study Forum Helper

Original post by James2301

Also on Question 7 (i) and (ii) I got those answers, but I don't believe I did it with the intended method. I formed two simultaneous equations to find Z1 and Z2, then did Z1 - Z2 and found a complex number, I then typed the values into my Calculator and came out with those exact values. Will I still get the marks for this or will I lose some?

Finally, how would you compare the difficulty of this paper to previous years?

Right answer = full marks.

I can't really compare difficulties.

Reply 9

Mr M

Study Forum Helper

Original post by shreys

1. right quadrant and labelled = full marks

2. so did I! drop 1 mark

3. 1 mark for no plus or minus and possibly lose more if other stuff was wrong

Reply 10

shreys

Original post by Mr M

Right answer = full marks.

I can't really compare difficulties.

Dear Mr M,

Thanks for this again.

Just a few questions:

1.On the Argand diagram drawing one I drew the correct angles for the first two (z1 and z2), however didn't include a scale. How many marks would I drop?

2. On the question for finding p, I made a simple arithmetic mistake and got p=-2, not p=-1. How many would I lose for this?

3. On the final question, I made a small mistake and got close to the answer, but not the actual answer. I got most of the working right, however I accidentally also only put one b value, not plus or minus. How many marks would I lose for this?