Cambridge International A Level: Mathematics 9709/32
Cambridge International A Level: Mathematics 9709/32
MATHEMATICS 9709/32
Paper 3 Pure Mathematics 3 February/March 2024
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 2024 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 points.
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.
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 specifically 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 significant 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)
Obtain quotient x 2 − 3 x + 4 A1 A = 1, B = −3
[5A + C = 9 so C = 4; 5B + D = − 12 so D = 3;
5C + E = 27 so E = 7].
A pair of incorrect statements ‘remainder
x 2 − 3 x + 4 ’ and ‘quotient 3 x + 7 ’ score M1 A1
A0.
Obtain remainder 3 x + 7 A1
x2 − 3x + 4 3
x2 + 5 x4 – 3x3 + 9x2 – 12x + 27
x4 + 5x2
− 3x + 4x2
3
− 3x3 − 15x
+ 4x2 + 3x
+ 4x2 + 20
+ 3x +7
(( − 3 ) )
3(a) Obtain r = 4 B1
( )
2 2 2
z = + 12 so r =
z =− 3 + 12 .
B1
( )
2
z2 = 2 – 2 3 i so r = 22 + – 2 3 =4
Obtain 1 −i
2π
and
π
1 i3 A1
3
e 3
3
e
3
© Cambridge University Press & Assessment 2024 Page 8 of 18
9709/32 Cambridge International A Level – Mark Scheme February/March 2024
PUBLISHED
Question Answer Marks Guidance
4 Obtain ln p − ln q =
a B1 p a
=e .
q
Obtain ln p + 2ln q =
b B1 pq2 = eb .
13a + 8b A1
Obtain
3
p
x B1 p
( ) Or ln=
p 7 q x ln + y ln q 2 p .
y
State p q = q 2 p
7
q
q
Equate indices to form simultaneous equations in x and y, can have errors M1 x + y = 7 and − x + 2y = 1.
Obtain 7= x + y and =
1 2y − x A1 Leading to
= x 13
= , y 8 .
3 3
13a + 8b A1
Evaluate x × a + y × b to obtain
3
5(b) Carry out a complete method for finding the greatest value of arg z M1 2+2 2
e.g. tan −1 .
5
Allow 2√2 as √(32 − 12 ).
6(a) State or imply 4 y ddyx as the derivative of 2 y 2 B1 SC If dy introduced instead of d then allow B1
dx dx
for both, followed by correct method M1 Max 2.
State or imply 3 y + 3 x ddyx as the derivative of 3xy B1 Allow extra dy = correct expression to collect all
dx
marks if correct.
6(b) Equate numerator to zero, obtaining 2x = 3y + 1 or 3y = 2x −1 and form equation in M1* e.g. 2
( 2 x − 1)2 + x ( 2 x − 1) + x = x2
x only or y only from 2y2 +3xy + x = x2 9
2 y 2 + 32 (1 + 3 y ) y + 12 (1 + 3 y ) = 14 (1 + 3 y ) .
2
or
Allow errors.
Obtain 92 ( 2 x − 1) =
2
− x 2 or a 3 term quadratic in one unknown and try to solve. DM1 e.g. 17 x 2 − 8 x + 2 = (
0 b 2 − 4ac =
−72 )
If errors in quadratic formulation allow solution, applying usual rules for solution of
quadratic equation, and allow M1
or 17 y 2 + 6 y + 1 = ( −32 .
0 b 2 − 4ac = )
x = 4/17 ± (3√2/17)i, y = − 3//17 ± (2√2/17)i .
Conclude that the equation has no [real] roots A1 Given Answer. CWO
7(b) Calculate the value of a relevant expression or values of a pair of expressions at M1 Need to attempt BOTH values and have one
x = 0.4 and x = 0.5 correct.
Complete the argument correctly with correct calculated values A1 e.g. 0.4 < 0.51[ 08] and 0.5 > 0.458 or 0.46 or
0.45
or – 0.11[08] < 0 and 0.042 > 0
If use original derivative −0.994 (0.4) and
0.437 (0.5).
Show sufficient iterations to 4 d.p. to justify 0.47 to 2 d.p. or show there is a sign A1 0.4,0.5108,0.4528,0.4823,0.4670,0.4749
change in the interval ( 0.465, 0.475 ) 0.45,0.4838,0.4663,0.4753,0.4707,0.4730
0.5,0.4581,0.4795,0.4685,0.4742
Allow self correction.
3 SC B1 No working 0.47
Use correct trig formulae to find α M1 α = tan−1 (b/a) from their a sin x + b cos x
or sin−1 or cos−1 provided this expression obtained
by correct method.
NB If cos α = 1 and sin α = 2 then M0 A0.
Obtain second correct answer e.g. 2.60 (2.5986) or 4π – 0.74 = 11.8 A1 If uses 1.11° withhold first accuracy mark gained,
or 2.60 − 4π = −9.97 in the interval but allow rest of accuracy marks. Allow 2.6(0).
Obtain two more correct answers e.g. −9.97 and 11.8 and no others in the interval A1 Ignore answers outside the interval. Treat answers
in degrees as a misread.
( −571.1°, − 42.6°,148.9°, 677.2° ) .
5
Show the diagonals bisect each other at ( 4,1, −3) OB 1
= OC + ( OA − OC ) = (4, 1, −3).
2 2
Show the quadrilateral is a parallelogram e.g. OB =OA + OC .
Show both pairs of opposite sides are equal in length and a pair of adjacent sides are
perpendicular
Using the correct process for the moduli, divide the scalar product by the product of M1 44
the moduli and obtain the inverse cosine of the result. ± cos −1 .
104
For any two vectors.
Using the correct process for the moduli, divide the scalar product by the product of M1 30 74
the moduli and obtain the inverse cosine of the result. Any two vectors. ± cos −1 −1
or cos .
104 104
Required angle = 180° − 2 × 57.5° or 180° − 2 × 32.5° = 115° and 180° − 115° or B1 OE SOI
2× 32.5° Complete method to find the acute angle.
5 Dx + E C
SC + B0 M1 and C = −16
4 a ^ 2 − x ^ 2 5a − 2 x
A1 Max 2/5.
SC Allow M1 only for other incorrect partial
fraction.
10(b) Integrate and obtain one of the terms ln 2a + x − 9ln 2a − x + 8ln 5a − 2 x B1 FT Condone missing modulus signs.
Use their A, B and C.
Obtain the third correct term B1 FT Max 3/5 if value is assigned for a (award M0 A0).
Substitute limits correctly in an integral of the form M1 Either (i) collect terms with same coeeficient and
p ln 2a + x + q ln 2a − x + + r ln 5a − 2 x and remove all a’s remove all a’s
e.g. pln 3a −pln a + qln a − qln 3a + rln 3a –
rln7a
hence pln 3 − qln 3 + rln 3 − rln7
or
(ii) collect same ln terms and remove all a’s
e.g. (p – q + r) ln 3a – ( p – q) ln a – rln7a
and − (p − q) ln a = (−p + q − r ) ln a + r ln a
hence p ln 3 – q ln3 + rln 3 – r ln 7.
Obtain 18ln 3 − 8ln 7 from correct working A1 A0 if the solution involves logarithms of negative
numbers.
Integrate to obtain p (1 + y ) e −3 y + qe −3 y dy M1 Allow unless clear evidence that formula used has
∫ a + sign.
−1 1 A1 Allow unsimplified.
Obtain (1 + y ) e−3 y + e−3 y dy
∫
3 3
1 B1
Use correct double angle formula to obtain ∫ 2cos 2 θ
dθ
π M1* 1 1 1 17
Use y = 0, θ = to evaluate a constant of integration in an expression of the form =− − + C C =
4 2 3 9 18
y y
α ye −3 y , β e −3 y and γ tan θ only. Allow αye and βe . Must have integrated LHS
3 3
twice.
Use y = 1 DM1 − (1 + 1) 1 17
3
− 1( 9e3 ) = tan θ − .
3e 2 18
Must have integrated LHS.