IB Maths AA HL November 2023: what the examiners reported

Section A of Paper 1 and most of Paper 2 went well, with continued gains in calculator use and solid work on vectors, differential equations and rational functions. Induction for divisibility, complex equations, trig identities from De Moivre, 3D vector reasoning, transformed random variables and formal proof on Paper 3 remained the main obstacles.

By Pietro Meloni, PhD · Summarised from the IB subject report on

Maths AA HL grade boundaries, November 2023 TZ2: minimum mark for each grade. Every session
ComponentMax4567
Overall10034476178
Internal assessment209121517
Paper 111037486486
Paper 211039516485
Paper 35515243442

HL Paper 1

Routine questions were answered confidently, but induction, complex equations and limits caused trouble and presentation was often scattered across the page.

Found difficult

  • proof by induction
  • complex numbers
  • trigonometric identities

Well prepared

  • laws of logarithms
  • differentiation rules
  • sequences and series
  • integration by parts
HL Paper 1: question by question, in my words.
QTopicHow it wentWhere marks were lost
1straightforward opening questionAnswered welloccasional arithmetic slip in (b)
2probability of a union of eventsAnswered wellNothing specific reported.
3arithmetic sequence from two linear equationsAnswered wellwork scattered around the page; basic subtraction slip in (b)Tip: Keep each line of working in order so you can check your own results.
4area of a triangle using sin of an angleMixedcould not find sin BAC or did not think to; error-prone use of half base times heightTip: Find sin of the angle from cos via a right triangle or identity, then use (1/2)ab sin C.
5binomial expansion to find n and kAnswered welldid not cancel powers of x before forming equations
6proof by induction for divisibilityMost struggledstalled after writing P(k+1); unclear about what is assumed and what is provedTip: Rewrite the k+1 expression so the assumed multiple appears, then factor out the divisor.
7complex equation by equating real and imaginary partsMixedsquared 5 + qi incorrectly; did not equate real and imaginary partsTip: Expand carefully remembering i^2 = -1, then match real and imaginary parts.
8repeated integration by partsAnswered wellsign slip on one term; unclear derivation of the given answer involving ln 4
9even function and a trigonometric limitMixedclaimed f(-x) = f(x) without intermediate steps; omitted limit notationTip: Show f(-x) step by step and keep writing 'lim' until the limit is taken.
10logarithms, discriminant and sequencesAnswered welldid not reject the d < 0 solutionTip: Check each solution against the conditions in the question.
11stationary points, sketch and Maclaurin seriesMixedgave x-values instead of full coordinates; sketches too small with wrong concavity at endpoints; differentiated cos 2x repeatedly instead of using the known series; did not see that the last part only needed multiplying by eTip: Build new Maclaurin series from booklet ones by substitution rather than differentiating.
12De Moivre expansion and roots of a trig polynomialMost struggleddid not collect real and imaginary terms; equated imaginary parts and stopped; could not explain why roots of sin 5θ give roots of the quarticTip: Link the trig equation to the polynomial explicitly and justify which roots carry over.

What to practise

  • Practise induction proofs for divisibility.
  • Keep diagrams a reasonable size and sketch graphs with care.
  • Present arguments line by line in a consistent sequence.

HL Paper 2

Generally well done with improving calculator use and broad HL knowledge, although some still used unsuitable algebra and lost accuracy through rounded intermediate values.

Found difficult

  • kinematics
  • inequalities
  • vectors, lines and planes
  • linear transformation of random variables
  • normal distribution

Well prepared

  • arcs and sectors
  • scalar and vector products
  • rational functions
  • counting principles
  • discrete random variables
  • normal distribution
HL Paper 2: question by question, in my words.
QTopicHow it wentWhere marks were lost
1length and angle in a 3D solidMixedgave a vector instead of a length; used position vectors instead of edge vectors; found an area instead of the angle; premature roundingTip: Notation like BV means a length, so give a number, not a vector.
2graph sketch and parameter valueMixedendpoints poorly positioned; gave k as 2 instead of 1/2
3area and perimeter from circles and sectorsAnswered wellmissed some lengths in the perimeterTip: List every boundary piece before adding up a perimeter.
4particle motion and distance travelledMost struggleddifferentiated by hand before integrating the modulusTip: Distance travelled is the integral of |velocity|; let the calculator do it.
5discrete distribution with unknownsMixedfound k but did not go on to a; forgot that probabilities sum to 1Tip: Use both conditions: probabilities total 1 and the given expected value.
6binomial mean and varianceAnswered wellused the general variance formula instead of np(1-p)
7counting arrangements and selectionsMost struggledadded where they should multiply or vice versa; used permutations instead of combinationsTip: Multiply for successive choices, add for separate cases.
8minimising a distance with a parameterMixedexpanded the squared magnitude and made errors; gave the minimising p but not the minimum value; assumed p was an integerTip: Answer what is asked: the minimum value, not just where it occurs.
9Euler's method and solving a first-order differential equationAnswered wellcalculated each Euler step separately; mishandled the constant of integration; gave percentage instead of absolute errorTip: Write the iteration formula and use the calculator's recursion to list values.
10normal distribution: inverse normal, discrete counts and IQRMixedsubstituted probabilities into the z formula; used at most 49 instead of fewer than 49; premature roundingTip: For a discrete count, 'fewer than 49' means at most 48.
11rational function with an oblique asymptote and inequalityMixeddrew only one branch; curves moving away from asymptotes; values not to 3 significant figures; algebraic attempts at the inequalityTip: Draw both branches approaching every asymptote, using a ruler for axes and asymptotes.
12reflection in a plane and lines lying in a planeMixedno reasoned argument that the point exists; checked only one point to show a line lies in the plane; algebraic slipsTip: A line lies in a plane only if a point is on it and its direction is perpendicular to the normal.

What to practise

  • Teach students when a calculator method is suitable and how to record it.
  • Avoid rounding intermediate values; give answers exactly or to 3 significant figures.
  • Practise clear sketches with endpoints and asymptotic behaviour.
  • Teach the guide's notation for segments, angles, lines and interval sets.
  • Build conceptual understanding in kinematics.

HL Paper 3

Most candidates attempted both investigations within the hour; cubic families with parameters, formal direct proof and the homogeneous differential equation were the hard parts.

Found difficult

  • parameters in functions
  • show that and proof reasoning
  • graph sketching
  • chain rule
  • differential equations
  • integration techniques
  • limits

Well prepared

  • graphing with the calculator
  • stationary and inflexion points
  • differentiation rules
  • tangents and normals
  • differential equations
  • implicit differentiation
HL Paper 3: question by question, in my words.
QTopicHow it wentWhere marks were lost
1cubic graphs with parameters: intercepts, turning points and a proofMixedinteger sets instead of real inequalities for b; did not substitute x into y to complete a show-that; wrong conclusions about which turning point is above the axis; divided by b without checking b is non-zeroTip: Before dividing by an expression, state why it cannot be zero, or split into cases.
2orthogonal families of curves and a homogeneous differential equationMixedsketched only half of each curve or left them unlabelled; did not justify dividing by a + b; chain rule errors instead of implicit differentiation; could not integrate 1/x or the v-expression; misused L'Hopital for the final limitTip: Two curves meet at right angles when the product of their gradients there is -1.

What to practise

  • Practise Paper 3 style questions, including parts with several answers.
  • Discuss command terms and exact-value requirements.
  • Use sliders to show how parameters change graphs.
  • Discourage working backwards from given answers and avoid graph paper.

Internal assessment

What moderators raised about the exploration this session, criterion by criterion.

  • A. plans written in the introduction, aims too ambitious and tiny fonts or single spacing used to fit pages
  • A. sources left out of the bibliography or padded bibliographies; AI use not acknowledged
  • B. unlabelled diagrams, computer notation and unexplained terms from outside the syllabus
  • C. hard work and effort mistaken for personal engagement; textbook or historical topics limit ownership
  • D. visual readings of graphs and descriptions of results instead of evaluating strategies
  • E. mathematics either too far beyond the course to explain or no deeper than SL
  • E. correlation used without understanding causality or testing dependence

About this summary

After every session the IB sends schools a subject report: how candidates did on each paper and question, and what teachers should work on. This page is my reading of the Maths AA HL report for November 2023, in my own words. No text from the report or from the exam questions is reproduced, and it is not endorsed by the International Baccalaureate.

Session codes: TZ is the time zone variant of the papers. Corrections: pietro@pietromeloni.com.

Frequently asked questions

Which questions were hardest in Maths AA HL November 2023?

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The questions most candidates struggled with were on proof by induction for divisibility, De Moivre expansion and roots of a trig polynomial, particle motion and distance travelled and counting arrangements and selections. The tables above list every question discussed in the report, paper by paper.

What did candidates find difficult in November 2023?

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Across the papers the examiners listed proof by induction, complex numbers, trigonometric identities, kinematics, inequalities, vectors, lines and planes, linear transformation of random variables and normal distribution, among others.

What were the grade boundaries for Maths AA HL November 2023?

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Maths AA HL: a 7 from 78 out of 100 overall in November 2023 TZ2. The component boundaries are in the table on this page.

Is this the official IB subject report?

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No. It is my summary of the report the IB issues to schools after each session, rewritten in my own words with a teacher's reading of it. No text from the report or from exam questions is reproduced. Your school's IB coordinator can access the original.

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