User interface language: English | Español

Date May 2012 Marks available 3 Reference code 12M.1.sl.TZ1.14
Level SL only Paper 1 Time zone TZ1
Command term Find Question number 14 Adapted from N/A

Question

A function f (x) = p×2x + q is defined by the mapping diagram below.

Find the value of

(i) p ;

(ii) q .

[3]
a.

Write down the value of r .

[1]
b.

Find the value of s .

[2]
c.

Markscheme

(i) 2p + q = 11 and 4p + q = 17     (M1)

Note: Award (M1) for either two correct equations or a correct equation in one unknown equivalent to 2p = 6 .

 

p = 3     (A1)

 

(ii) q = 5     (A1)     (C3)

Notes: If only one value of p and q is correct and no working shown, award (M0)(A1)(A0).

 

[3 marks]

a.

r = 8     (A1)(ft)     (C1)

Note: Follow through from their answers for p and q irrespective of whether working is seen.

[1 mark]

b.

3 × 2s + 5 = 197     (M1)

Note: Award (M1) for setting the correct equation.

 

s = 6     (A1)(ft)     (C2)

Note: Follow through from their values of p and q.

[2 marks]

c.

Examiners report

Candidates both understood how to interpret a mapping diagram correctly and did very well on this question or the question was very poorly answered or not answered at all. Writing down two simultaneous equations in part (a) proved to be elusive to many and this prevented further work on this question. Candidates who were able to find values of p and q (correct or otherwise) invariably made a good attempt at finding the value of s in part (c).

a.

Candidates both understood how to interpret a mapping diagram correctly and did very well on this question or the question was very poorly answered or not answered at all. Writing down two simultaneous equations in part (a) proved to be elusive to many and this prevented further work on this question. Candidates who were able to find values of p and q (correct or otherwise) invariably made a good attempt at finding the value of s in part (c).

b.

Candidates both understood how to interpret a mapping diagram correctly and did very well on this question or the question was very poorly answered or not answered at all. Writing down two simultaneous equations in part (a) proved to be elusive to many and this prevented further work on this question. Candidates who were able to find values of p and q (correct or otherwise) invariably made a good attempt at finding the value of s in part (c).

c.

Syllabus sections

Topic 1 - Number and algebra » 1.6 » Use of a GDC to solve pairs of linear equations in two variables.

View options