Cambridge International A Level: Mathematics 9709/32
Cambridge International A Level: Mathematics 9709/32
MATHEMATICS 9709/32
Paper 3 Pure Mathematics 3 February/March 2025
MARK SCHEME
Maximum Mark: 75
Published
This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.
Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report f or
Teachers.
Cambridge International will not enter into discussions about these mark schemes.
Cambridge International is publishing the mark schemes f or the February/March 2025 series f or most
Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level
components.
These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the specific content of the
mark scheme or generic level descriptions for a question. Each question paper and mark scheme will also comply with these marking principles.
1 Unless a particular method has been specified in the question, full marks may be awarded for any correct method. However, if a calculation is required
then no marks will be awarded for a scale drawing.
2 Unless specified in the question, non-integer answers may be given as fractions, decimals or in standard form. Ignore superfluous zeros, provided that the
degree of accuracy is not affected.
3 Allow alternative conventions for notation if used consistently throughout the paper, e.g. commas being used as decimal point s.
4 Unless otherwise indicated, marks once gained cannot subsequently be lost, e.g. wrong working following a correct form of answer is ignored (isw).
5 Where a candidate has misread a number or sign in the question and used that value consistently throughout, provided that number does not alter the
difficulty or the method required, award all marks earned and deduct just 1 A or B mark for the misread.
6 Recovery within working is allowed, e.g. a notation error in the working where the following line of working makes the candidate’s intent clear.
Examiners use a system of annotations as a shorthand for communicating their marking decisions to one another. Examiners are trained during the standardisation
process on how and when to use annotations. The purpose of annotations is to inform the standardisation and monitoring processes and guide the supervising
examiners when they are checking the work of examiners within their team. The meaning of annotations and how they are used is specific to each component and
is understood by all examiners who mark the component.
We publish annotations in our mark schemes to help centres understand the annotations they may see on copies of scripts. Note that there may not be a direct
correlation between the number of annotations on a script and the mark awarded. Similarly, the use of an annotation may not be an indication of the quality of the
response.
The annotations listed below were available to examiners marking this component in this series.
Annotations
Annotation Meaning
Blank Page
Incorrect point
Follow through
Judgement
Judgement
Misread
Off-page Allows comments to be entered at the bottom of the RM marking window and then displayed when the associated question item is
comment navigated to.
Premature approximation
Special case
Correct point
Transcription error
The following notes are intended to aid interpretation of mark schemes in general, but individual mark schemes may include marks awarded for specific reasons
outside the scope of these notes.
Types of mark
M Method mark, awarded for a valid method applied to the problem. Method marks are not lost for numerical errors, algebraic slips or errors in units.
However, it is not usually sufficient for a candidate just to indicate an intention of using some method or just to quote a formula; the formula or idea
must be applied to the specific problem in hand, e.g. by substituting the relevant quantities into the formula. Correct application of a formula
without the formula being quoted obviously earns the M mark and in some cases an M mark can be implied from a correct answer.
A Accuracy mark, awarded for a correct answer or intermediate step correctly obtained. Accuracy marks cannot be given unless the associated method
mark is earned (or implied).
DM or DB When a part of a question has two or more ‘method’ steps, the M marks are generally independent unless the scheme specificall y says otherwise;
and similarly, when there are several B marks allocated. The notation DM or DB is used to indicate that a particular M or B mark is dependent on
an earlier M or B (asterisked) mark in the scheme. When two or more steps are run together by the candidate, the earlier marks are implied and full
credit is given.
FT Implies that the A or B mark indicated is allowed for work correctly following on from previously incorrect results. Otherwise, A or B marks are
given for correct work only.
• A or B marks are given for correct work only (not for results obtained from incorrect working) unless follow through is allowed (see abbreviation FT above).
• For a numerical answer, allow the A or B mark if the answer is correct to 3 significant figures or would be correct to 3 sign ificant figures if rounded (1
decimal place for angles in degrees).
• The total number of marks available for each question is shown at the bottom of the Marks column.
• Wrong or missing units in an answer should not result in loss of marks unless the guidance indicates otherwise.
• Square brackets [ ] around text or numbers show extra information not needed for the mark to be awarded.
AG Answer Given on the question paper (so extra checking is needed to ensure that the detailed working leading to the result is valid)
CAO Correct Answer Only (emphasising that no ‘follow through’ from a previous error is allowed)
SC Special Case (detailing the mark to be given for a specific wrong solution, or a case where some standard marking practice is to be varied in the
light of a particular circumstance)
Use correct method to solve an equation of the form e±2 x = a, where a > 0, and a M1 E.g. [e–2 x = 1 − e–3 ]
reasonable attempt at the B1, for ± 2x ln e or ± x ln e −2x = ln(1 − e–3 ) … OE.
Can be numerical ln (1 − 0.049787) = ln 0.9502.
Evidence of method must be seen.
Rearrange to obtain an expression for ex and solve an equation of the form e±x = a, M1 1 e3
where a > 0, and a reasonable attempt at the B1, for x E.g. e x = , e x
= ,
1 − e −3 e3 − 1
1
x = ln
1 − e −3
Can be numerical.
Evidence of method must be seen.
2 dy B1
1+ 2
State or imply dx as the derivative of ln (x + 2y)
x + 2y
dy B1 dy
State derivative of xy2 is x2y + y2 x2 y + y2
dx dx
dy B1 OE
1+ 2 May be implied by correct final answer.
dy dx = 0
Obtain y 2 + 2 xy +
dx x + 2 y
1 B1 OE
Obtain y = e when x = 0 Allow 12 2.718 or 1.36 or better e.g. 1.359…
2
May be implied by correct final answer.
( )
dy 1 B1 OE
Obtain = − e3 + 4 Accept AWRT –3.01. ISW.
dx 8
Carry out a correct method for finding the greatest value of | z | DM1
4 tan x − 3 B1 OE
State Allow decimals throughout.
1 + 3 tan x
2 B1 SOI
2 cot x replaced by
tan x
Reduce the equation to tan² x – 3 3 tan x – 2 = 0, or three-term equivalent B1 May be implied by further work.
Solve a three-term quadratic in tan x, for x M1 FT their 3-term quadratic. Allow tan–1 (..).
Obtain the second answer, e.g. 160.2° and no other in the interval A1 Allow 160, or AWRT 160.2.
Treat answers in radians as a misread.
Ignore answers outside the given interval.
( )
2
( −4 )
2
or x2 + y 2 = + 6 5
Eliminate one variable and find a horizontal equation in the other M1 Allow slips in e.g. signs, powers etc.
Separate variables correctly and reasonable attempt at integration of at least one side M1 Position of (x + 5) or ( 15 x + 1) and sin2 2θ
sufficient for correct separation.
1 B1 OE
Obtain term 5ln x + 1 May see 5ln ( x + 5 ) .
5
1 1 B1 FT 1 1 1
Obtain term ( − sin 4 ) Allow sin 4 from = ( 1 ± cos 4θ).
2 4 2 4 2
1 A1 FT 1
Obtain final answer x = 10exp − sin 4 − 5 or equivalent
1 1
x = 10exp sin 4 − 5
10 4 2 4
with ln removed Must remove ln from
1 1
ln ( x + 5 ) = ( sin 4 ) + ln 10.
2 4
1 3 A1 AG
Equate correct derivative to zero and obtain p = tan −1 after full and correct Must reach tan 2p = … or tan 2x = … before given
2 2p answer.
working
7(b) Calculate the values of a relevant expression or pair of expressions at x = 0.5 and M1 1 3
x = 0.7 Must have at least 1 of 2 values correct or 3 of 4 values correct f(p) = p − tan −1
2 2p
f(0.5) = –0.124… < 0, f(0.7) = 0.132.. > 0
1 3
or comparing p and tan −1 .
2 2p
1 −1 3
0.5 tan = 0.624 0.5 < 0.624…
2 2p
1 −1 3
0.7 tan = 0.567 0.7 > 0.567
2 2p
Show sufficient iterations to at least 5 decimal places to justify 0.596 to 3 decimal A1 E.g. 0.5, 0.62452, 0.58814, 0.59856, 0.59556,
places or show there is a sign change in the interval (0.5955, 0.5965) 0.59642
Obtain correct answer for λ or for μ A1 Possible answers are 6, 12, 0 for λ and
–9, –21, –3 for μ.
Verify that one component equation is not satisfied A1 E.g. show 21 ≠ 15 for (11, 21, –10) and
Can show by correctly obtaining 2 values of λ or 2 values of μ (11, 15, –10),
or show –16 ≠ –22 for (23, 39, –16) and
(23, 39, –22),
or show –1 ≠ 5 for (–1, 3, – 4) and (5, 3, – 4).
Using the correct process for the moduli, divide the scalar product by the product of M1 Allow for any pair of vectors here but must be
the moduli and evaluate the inverse cosine of the result consistent between scalar product and magnitudes.
9(a) Substitute x = 3 or –3 into p (x) and equate to 0 or into p' (x) and equate to 72 M1*
Obtain 162 + 9a + 3b + 9 = 0 A1 OE
Obtain 162 + 6a + b = 72 A1 OE
Solve simultaneous equations to obtain either a or b after using p (±3) = 0 and DM1
pꞌ (±3) = 72
9(b) Equate (x – 3)(6x2 + Ax + B) to 6x3 – 11x2 – 24x + 9 and obtain equations to solve for M1 Using their a and their b.
A and B A – 18 = a = − 11, B – 3A = − b = − 24,
− 3B = 9.
A = 7 and B = –3.
or divide 6x3 – 11x2 – 24x + 9 by x – 3 and reach 6x2 ± 7x Or reach 6x2 ± (their a + 18) x.
(x – 3)(6x2 + 7x – 3) A1 SOI
3 1 B1 FT 3 1
Obtain both regions x − , x 3 Allow x − and x 3.
2 3 2 3
3 1
SC B1 for x − , x 3.
2 3
FT is on the last two brackets (not ( x – 3)).
If incorrect factor or factors in (b) but correct
regions here, allow SC B1 only.
10(a) A Bx + C B1
State or imply the form +
1 + x (
( ) 4 + x2 )
Use a correct method for finding a constant Even with incorrect PF denominators M1 A( 4 + x 2 ) + (Bx + C)(1 + x) + = −7 x 2 +2x − 6
A C
Special Case 1: + + Find A,
( )
(1 + x ) 4 + x 2
M1 A1. Max 2/5.
A Bx
Special Case 2: + + Find A,
( )
(1 + x ) 4 + x 2
M1 A1. Max 2/5.
Obtain integral of the form c tan −1 dx with d ≠ 1 following separation into two M1 d = 1
2
or 2 only.
expressions
x A1 FT C −1 x
Obtain 3tan −1 FT tan
2 2 2
Substitute correct limits correctly in an expression (obtained correctly) of the form M1 a ln (3) + b ln (8) − b ln (4) + c ( 1 π ) , where
a ln (1 + x), b ln (4 + x2 ), and c tan −1 ( 12 x ) , where a, b, c ≠ 0.
4
a, b, c ≠ 0.
Do not allow slips, and must get to c ( 14 π ).
11 1 1 *M1 OE
Commence integration by parts and reach Ax 2 sin x Bx sin xdx BOD on ± otherwise scores 0/6.
3 3
1 1 A1 OE
Obtain 3x 2 sin x − 6 x sin x dx Allow 3×2 for 6.
3 3
1 1 1 *DM1 OE
Complete integration by parts and reach Ax 2 sin x + Bx cos x + C sin x
3 3 3
Substitute limits correctly in an expression of the form DM1 Dependent on both previous M1 marks.
1 1 1
Ax 2 sin x + Bx cos x + C sin x , where ABC ≠ 0 π 3 π 1
Need to use sin = , and cos = to obtain
3 3 3 3 2 3 2
3 Bπ C 3
Aπ 2 + + .
2 2 2
3 3 2 A1 27 3 3 18 54
Obtain answer π + 9π − 27 3 or exact equivalent ISW Allow for , for 9, for 27,
2 2 2 2 2
2187 for 27 3 etc.
1 1 *M1
Commence integration by parts and reach Ax 2 sin x + Bx cos x
3 3
1 1 A1 OE
Obtain 3x 2 sin x + 18x cos x Allow 6 × 3 for 18.
3 3
1 1 1 *DM1
Complete integration by parts and reach Ax 2 sin x + Bx cos x + C sin x
3 3 3
11 1 1 1 A1 OE
Obtain 3x2 sin x + 18 x cos x − 54sin x Allow 6 × 3 for 18, 9 × 6 for 54, OE.
3 3 3