IB Maths AA HL May 2025 TZ3: what the examiners reported

Logarithms, L'Hopital's rule and basic vectors, trigonometry and calculus were solid, but many Paper 1 scripts were untidy and a normal-distribution question was widely left blank. Paper 2 showed heavy reliance on slow analytic methods instead of the calculator, plus rounding problems, and Paper 3 exposed weak rigour in induction and limits.

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

Maths AA HL grade boundaries, May 2025 TZ3: minimum mark for each grade. Every session
ComponentMax4567
Overall10038516476
Internal assessment209121517
Paper 111031445770
Paper 211043577185
Paper 35527344148

HL Paper 1

Some topics looked unprepared, notably normal probabilities and volumes about the y-axis, and disorderly work in multi-stage questions caused many avoidable errors.

Found difficult

  • normal distribution
  • volumes of revolution
  • graph sketching
  • presentation of working

Well prepared

  • l'hopital's rule
  • laws of logarithms
  • vectors, lines and planes
  • trigonometric identities
  • differentiation rules
HL Paper 1: question by question, in my words.
QTopicHow it wentWhere marks were lost
1logarithms and change of baseAnswered welldid not know the change of base formula; worked backwards unsuccessfullyTip: Learn the change of base rule and use it to put all logs in one base.
2functions and their inverseAnswered wellconfused the inverse function with the reciprocalTip: f^-1(x) is the inverse function, not 1/f(x).
3trigonometric equation leading to a quadratic in cos θMixedignored the given interval; kept an impossible solution with cos θ = 5/4; divided by cos θ and lost solutionsTip: Factorise instead of dividing by cos θ, and reject values outside [-1, 1].
4tangent line conditionMixeddid not use the discriminant; found the derivative but did not set it equal to mTip: A tangent touches once: set the derivative equal to the gradient or the discriminant equal to zero.
5normal distribution probabilities and symmetryMost struggledleft blank; misread the normal distribution notation; could not use symmetryTip: Sketch the bell curve, mark the mean and use symmetry to split the probabilities.
6sketching a related graph without its equationMixedasymptotes not shownTip: Always draw and label asymptotes on a sketch.
7solid rotated about the y-axisMost struggledwrong or missing limits; treated the constant r as a variableTip: Identify which letters are constants before setting up the integral in y.
8modulus and argument of a complex numberMixedgot only one of modulus and argument right; unclear working in (b)
9limit by L'Hopital's ruleAnswered welldid not check the indeterminate form firstTip: State that the limit is of the form 0/0 before applying L'Hopital's rule.
10multi-part questionMixeddifficulties in (c)(i) and (c)(iii)
11multi-part questionMixeduntidy work full of errors; part (f) found hardestTip: Neat, ordered working prevents most careless slips in long questions.
12final long questionMost struggledran out of time after earlier partsTip: Budget time so the last section B question gets a fair attempt.

What to practise

  • Practise keeping work tidy and orderly; many scripts were unreadable.
  • Give more practice with long multi-stage questions.
  • Show students that a given answer lets them enter later parts even if they are stuck.

HL Paper 2

Standard trigonometry, probability and calculus went well, but many lost time and accuracy by solving analytically what the calculator could do, and rounding was poor.

Found difficult

  • tangents and normals
  • extended binomial theorem
  • counting principles
  • inverse trigonometric functions
  • related rates
  • conditional probability
  • differential equations
  • calculator use

Well prepared

  • trigonometry in triangles
  • discrete random variables
  • arcs and sectors
  • differentiation rules
  • scalar and vector products
  • kinematics
  • binomial distribution
  • tree diagrams
  • integration by parts
HL Paper 2: question by question, in my words.
QTopicHow it wentWhere marks were lost
1cosine and sine ruleAnswered wellgave BC squared instead of BC; calculator in radians; used right-angle methods
2remainder theorem with two unknownsMixederrors in synthetic or long division; did not finish the division to get the remainder; poorly organised workTip: Use the remainder theorem directly: substitute the root into the polynomial.
3discrete distribution: mode, mean and samplingMixedgave the mode as a probability; divided the mean by n; named quota sampling wronglyTip: E(X) = Σ x P(X = x) with no division; enter it as a list on the calculator.
4triangle area, radius and major arc lengthMixedused the wrong sides in the area formula or a sector area; found only the minor arcTip: For a major arc, use the reflex angle in s = rθ.
5quotient rule and gradient from an angleMost struggledswapped numerator terms in the quotient rule; equated f'(1) to 70 or to sin/cos of 70 degrees; gave a value outside the domainTip: The gradient of a line at angle θ to the horizontal is tan θ.
6scalar product and an equation in pAnswered wellsign errors; answer given as a vector; solved the equation by long algebra instead of the calculatorTip: Once you have one equation in one unknown, let the calculator solve it.
7extended binomial expansion with a parameterMost struggledwrong generalised binomial coefficient; sign errors; forgot the factor of q to a negative power; attempted a Maclaurin seriesTip: Factor the constant out first so the bracket starts with 1, then apply the formula carefully.
8counting games in a tournamentMost struggledexpressions in n given without explanation; miscounted the total number of gamesTip: Explain in words what each counting expression represents.
9related rates with arctanMost struggleddifferentiated with respect to x instead of t; omitted the factor 1/6 from the arctan derivative; did not use the calculatorTip: For a rate in time, use the chain rule: dθ/dt = dθ/dx × dx/dt.
10kinematics of a raceMixeddifferentiated by hand instead of using the calculator; used L'Hopital and got 0 or infinity for a limit; omitted the constant of integration; premature roundingTip: Use the calculator's derivative and integral tools on kinematics questions.
11binomial distribution and conditional probabilityMixedassumed independence for the intersection; left the unknown n part blank; recalculated a probability already found; did not multiply by 100 at the endTip: Find an unknown n with a table of binomial cdf values.
12integration by parts, integrating factor and sketching solutionsMost struggledsign and bracket errors in repeated parts; used y = vx or separation instead of an integrating factor; poor sketches ignoring the Ce^-x term; did not see each solution has its own constantTip: Draw axes with a ruler and scale, and keep the domain and constant term in mind when sketching.

What to practise

  • Teach calculator skills explicitly: solving equations, graphing derivatives and evaluating integrals.
  • After forming a single-variable equation, let the calculator solve it.
  • Enforce correct rounding and teach students to recall unrounded values.
  • Spend about half the time on each section.
  • Make sure students can extend formula booklet results, such as further binomial terms.

HL Paper 3

Algebra was mostly sound and both questions were accessible, but induction write-ups, limits and rigorous justification separated candidates.

Found difficult

  • proof by induction
  • limits
  • show that and proof reasoning

Well prepared

  • algebraic manipulation
  • composite functions
  • quadratic functions
  • differentiation rules
HL Paper 3: question by question, in my words.
QTopicHow it wentWhere marks were lost
1iterated linear functions, induction and limitsMixedextra term in the summation or wrong limits; vague induction statements and wrong base case; ignored -1 < m < 1 when finding the limit; missing brackets around -1 in (-1)^nTip: Write the inductive hypothesis precisely as 'assume P(k) is true', not 'assume n = k'.
2maximising the volume of a box and integer conditionsMixederrors simplifying the discriminant; set the second derivative to zero instead of evaluating it; no argument that the local maximum is global; ignored the condition t > 2sTip: When dividing an inequality by a variable, state that the variable is positive.

What to practise

  • Develop rigour in written mathematics, including assumption and conclusion statements in induction.
  • Use brackets and notation carefully.
  • Practise limits at infinity of algebraic expressions.
  • Stress that a show-that needs every step correct, ending at the stated result.

Internal assessment

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

  • A. poor flow, unnecessary methodology sections and evaluative comments added after the conclusion
  • B. graphs with faint or missing labels, tables of variables at the start and broken layout
  • B. approximation signs only at the end and no stated degree of accuracy
  • C. heavily sourced work and extra irrelevant models showing little original thinking
  • D. reflection given as a list of observations rather than ongoing critical review
  • E. techniques beyond the course used without understanding, or work not going beyond SL
  • E. technology results taken on trust without checks or interpretation

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 May 2025 TZ3, 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. Other variants of the same session: May 2025 TZ2, May 2025 TZ1. Corrections: pietro@pietromeloni.com.

Frequently asked questions

Which questions were hardest in Maths AA HL May 2025 TZ3?

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The questions most candidates struggled with were on normal distribution probabilities and symmetry, solid rotated about the y-axis, final long question and quotient rule and gradient from an angle. The tables above list every question discussed in the report, paper by paper.

What did candidates find difficult in May 2025 TZ3?

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Across the papers the examiners listed normal distribution, volumes of revolution, graph sketching, presentation of working, tangents and normals, extended binomial theorem, counting principles and inverse trigonometric functions, among others.

What were the grade boundaries for Maths AA HL May 2025 TZ3?

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Maths AA HL: a 7 from 76 out of 100 overall in May 2025 TZ3. 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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