CensaiCensai
HSC Mathematics Extension 1 · 2026 Forecastcensai.com.au

HSC Mathematics Extension 1 2026 Forecast

Every question from the six HSC Mathematics Extension 1 papers of 2020–2025 (175 questions) has been mapped to the syllabus dot point(s) it assesses. Multiple-choice questions 1–10 are kept whole; from Question 11 each letter (a), (b), … is a separate question, with roman (i), (ii) kept together. The 2026 paper is the final examination of the 2017 syllabus; a new syllabus is taught from 2026 and first examined in 2027. Each dot point is tagged with its fate in the 2024 syllabus (kept, reduced, or removed), because content that is about to disappear has only one more chance to be examined.

Based on the NESA HSC Mathematics Extension 1 examinations 2020–2025, the Mathematics Extension 1 Stage 6 Syllabus (2017) and the Mathematics Extension 1 11–12 Syllabus (2024). Counts are questions, not marks. A question is counted once for each dot point it touches, so column totals exceed 175. This forecast is a study guide to help you prioritise revision; it is not a guarantee of what will be examined.

175
Questions reviewed (6 papers)
72
Syllabus dot points tracked
244
Dot-point hits recorded
6
Examined all 6 years
7
Examined once
8
Never examined
7
Removed or reduced in 2024
21
Past hits on removed content

Questions per paper by primary topic

Topic202020212022202320242025Total
Functions54864431
Trigonometric Functions34235623
Calculus8117711953
Combinatorics33332317
Proof1111116
Vectors46734731
Statistical Analysis12333214
Total253131263032175

Calculus and Vectors together are about half of every paper. Proof is almost always a single induction. Statistics is a small number of questions but a large share of the last-chance marks.

Dot-point hits by subtopic, 2020–2025

SubtopicHits
F1 Further Work with Functions
23
F2 Polynomials
18
T1 Inverse Trigonometric Functions
16
T2 Further Trigonometric Identities
8
T3 Trigonometric Equations
16
C1 Rates of Change
9
A1 Working with Combinatorics
21
P1 Proof by Mathematical Induction
6
V1 Introduction to Vectors
47
C2 Further Calculus Skills
26
C3 Applications of Calculus
29
S1 The Binomial Distribution
25

Further calculus skills, DEs/volumes, and vectors dominate. Inverse trig and combinatorics are steady supporting strands. t-formulae do not appear on the chart because they have never been examined.

Syllabus dot points × years examined

Row shading: green = examined every year, amber = examined once, red = never examined. “2024 syllabus” column: Kept / Reduced / Removed.

CodeSyllabus dot point202020212022202320242025TotalYears2024 syllabusQuestions (year·number)
Functions · ME-F1 Further Work with Functions23
F1.1aSketch y=1/f(x) from y=f(x); asymptotes1···1·22/6Kept2020·11C, 2024·12E
F1.1bSketch y^2=f(x) and y=√f(x) from y=f(x)······00/6Kept
F1.1cSketch y=|f(x)| and y=f(|x|) from y=f(x)··11··22/6Kept2022·02, 2023·08
F1.1dSketch y=f(x)+g(x) and y=f(x)−g(x)··1···11/6Kept2022·04
F1.2aSolve quadratic inequalities (algebra or graph)1···1·22/6Kept2020·01, 2024·11B
F1.2bSolve rational inequalities (unknown in denominator)··1·1·22/6Kept2022·11F, 2024·12E
F1.2cSolve |ax+b| ≥ k / ≤ k / < k / > k····1122/6Kept2024·12E, 2025·01
F1.3aOne-to-one, horizontal line test, restrict domain so an inverse exists·1221·64/6Kept2021·12D, 2022·09, 2022·13C, 2023·09, 2023·14A, 2024·14B
F1.3bFind f^{−1}(x); domain and range of an inverse11···133/6Kept2020·02, 2021·12D, 2025·11A
F1.4aParametric ↔ Cartesian for lines, parabolas, circles; sketch·111··33/6Kept2021·08, 2022·05, 2023·11A
Functions · ME-F2 Polynomials18
F2.1aRemainder theorem: remainder when P(x) is divided by x−α11·1··33/6Kept2020·11A, 2021·03, 2023·11C
F2.1bFactor theorem; factorise a cubic or quartic2··21·53/6Kept2020·05, 2020·11A, 2023·11C, 2023·14B, 2024·01
F2.1cPolynomial division: P=AQ+R, degree of remainder··1···11/6Kept2022·03
F2.2aSums and products of roots of quadratic, cubic or quartic11111276/6Kept2020·14B, 2021·11H, 2022·13D, 2023·14B, 2024·01, 2025·11F, 2025·14E
F2.2bMultiplicity of a root; if multiplicity > 1 then P'(α)=01·1···22/6Kept2020·05, 2022·13D
F2.2cGraph a polynomial from factored form / root multiplicity······00/6Kept
Trigonometric Functions · ME-T1 Inverse Trigonometric Functions16
T1aDefine sin^{−1}, cos^{−1}, tan^{−1}: domain, range, principal value··21··32/6Kept2022·01, 2022·13C, 2023·07
T1bSketch inverse-trig graphs and their transformations·2··1143/6Kept2021·09, 2021·12D, 2024·05, 2025·11D
T1csin(sin^{−1} x)=x and sin^{−1}(sin x)=x (and cos, tan) where valid·1·1·133/6Kept2021·09, 2023·05, 2025·14D
T1dOdd/even; sin^{−1}(−x); cos^{−1} x + sin^{−1} x = π/2···12143/6Kept2023·07, 2024·04, 2024·14C, 2025·06
T1eSolve equations / problems involving inverse trig1···1·22/6Kept2020·13C, 2024·14C
Trigonometric Functions · ME-T2 Further Trigonometric Identities8
T2aSum and difference expansions for sin, cos, tan·1····11/6Kept2021·13D
T2bDouble-angle formulae21··1154/6Kept2020·13A, 2020·14B, 2021·11G, 2024·13B, 2025·11B
T2ct-formulae: sin, cos, tan in terms of t=tan(x/2)······00/6Removed
T2dProduct-to-sum and sum-to-product identities1····122/6Removed2020·12D, 2025·11C
Trigonometric Functions · ME-T3 Trigonometric Equations16
T3aR-method: a cos x + b sin x = R sin(x±α) or R cos(x±α)11111166/6Kept2020·11D, 2021·07, 2022·11E, 2023·11E, 2024·10, 2025·12E
T3bSolve trig equations (factorise, compound or double angle)12·11385/6Kept2020·11D, 2021·11G, 2021·13D, 2023·11E, 2024·06, 2025·05, 2025·11B, 2025·12E
T3cProve further identities (e.g. sin 3θ, cos 3θ)1····122/6Kept2020·14B, 2025·14E
Calculus · ME-C1 Rates of Change9
C1.1aRates with respect to time; 1D particle language ẋ, ẍ······00/6Reduced
C1.2aExponential growth/decay Q=Ae^{kt}······00/6Kept
C1.2bNewton's law of cooling / carrying capacity Q=P+Ae^{kt}·211··43/6Kept2021·12B, 2021·14B, 2022·12D, 2023·01
C1.3aRelated rates of change (chain rule in context)11·11155/6Kept2020·10, 2021·11E, 2023·13A, 2024·11F, 2025·12A
Combinatorics · ME-A1 Working with Combinatorics21
A1.1aMultiplication principle; arrangements of distinct objects in a line······00/6Kept
A1.1bCircular arrangements···1·122/6Kept2023·10, 2025·13B
A1.1cPermutations with restrictions or repeated objects1··1··22/6Kept2020·08, 2023·11B
A1.1dCombinations nCr; committees and selections211·1·54/6Kept2020·08, 2020·12C, 2021·11D, 2022·07, 2024·09
A1.1ePigeonhole principle (simple results and proofs)·11·1144/6Removed2021·10, 2022·12B, 2024·03, 2025·14A
A1.1fProbability using permutations or combinations1···1·22/6Kept2020·12C, 2024·09
A1.2aBinomial expansion (a+b)^n; coefficient of a specified term111···33/6Kept2020·14A, 2021·11B, 2022·11C
A1.2bPascal identities; combinatorial proofs of binomial identities1··1·133/6Kept2020·14A, 2023·12D, 2025·13E
Proof · ME-P1 Proof by Mathematical Induction6
P1aProve a sum identity by induction11·1·144/6Kept2020·12A, 2021·12C, 2023·12B, 2025·12C
P1bProve a divisibility result by induction··1·1·22/6Kept2022·12F, 2024·12D
P1cIdentify errors in false inductions; when induction is not appropriate······00/6Kept
Vectors · ME-V1 Introduction to Vectors47
V1.1ai, j notation; addition, subtraction, scalar multiple121·1165/6Kept2020·04, 2021·01, 2021·11A, 2022·11A, 2024·11A, 2025·08
V1.1bGeometric addition/subtraction (triangle or parallelogram law)1·····11/6Kept2020·06
V1.2aMagnitude and unit vector··1·1133/6Kept2022·08, 2024·11A, 2025·09
V1.2bDirection of a vector; bearings and navigation·1····11/6Kept2021·14A
V1.2cDot product, angle between vectors, perpendicular condition125123146/6Kept2020·11B, 2021·05, 2021·14C, 2022·06, 2022·08, 2022·11A, 2022·11D, 2022·13A, 2023·14C, 2024·12A, 2024·13C, 2025·09, 2025·13C, 2025·14C
V1.2dParallel vectors a=kb··2··242/6Kept2022·06, 2022·14B, 2025·08, 2025·11E
V1.2eProjection of one vector onto another1·111155/6Kept2020·09, 2022·14B, 2023·06, 2024·13C, 2025·02
V1.2fDisplacement, force or velocity problems in 2D11···243/6Kept2020·04, 2021·14A, 2025·13C, 2025·14C
V1.2gGeometric proofs with vectors (parallelogram, midpoint, circle)·111··33/6Reduced2021·14C, 2022·13A, 2023·14C
V1.3aProjectile: derive/use x=Vt cos θ, y=Vt sin θ − ½gt²; range, height, time·1·11·33/6Kept2021·13B, 2023·13B, 2024·14D
V1.3bProjectile with calculus, unknown angle, or two particles··11·133/6Kept2022·14C, 2023·13B, 2025·14B
Calculus · ME-C2 Further Calculus Skills26
C2aIntegration by substitution (given substitution)21112296/6Kept2020·12D, 2020·13A, 2021·11C, 2022·11B, 2023·12A, 2024·11C, 2024·13D, 2025·03, 2025·11C
C2b∫sin² nx and ∫cos² nx using ½(1±cos 2nx)·1··1133/6Kept2021·02, 2024·13B, 2025·11G
C2cDerivative of an inverse: (f^{−1})'(x)=1/f'(f^{−1}(x))1111·155/6Kept2020·13C, 2021·14E, 2022·09, 2023·14A, 2025·10
C2dDerivatives of sin^{−1}, cos^{−1}, tan^{−1} (and chain rule)1·1·2154/6Kept2020·13C, 2022·12C, 2024·11E, 2024·14B, 2025·14D
C2eIntegrals 1/√(a²−x²) and 1/(a²+x²)11·1·144/6Kept2020·03, 2021·11F, 2023·11D, 2025·03
Calculus · ME-C3 Applications of Calculus29
C3.1aArea of the region between curves·1·12·43/6Kept2021·13C, 2023·04, 2024·02, 2024·11G
C3.1bVolume of a solid of revolution about the x-axis1·111155/6Kept2020·13B, 2022·13B, 2023·12E, 2024·12B, 2025·12B
C3.1cVolume about the y-axis, or the region between two curves·1····11/6Kept2021·13A
C3.2aDirection (slope) fields: identify, sketch, particular solution12211186/6Kept2020·07, 2021·04, 2021·12A, 2022·10, 2022·12A, 2023·03, 2024·13A, 2025·07
C3.2bSolve dy/dx=f(x)······00/6Kept
C3.2cSolve dy/dx=g(y)1·1··243/6Kept2020·11E, 2022·10, 2025·12D, 2025·13A
C3.2dSeparation of variables dy/dx=f(x)g(y); initial-value problems1·1·2154/6Kept2020·12E, 2022·14A, 2024·11D, 2024·14A, 2025·12D
C3.2eLogistic equation and modelling DEs·1··1·22/6Kept2021·14B, 2024·13A
Statistical Analysis · ME-S1 The Binomial Distribution25
S1.1aBernoulli random variable: E(X)=p, Var(X)=p(1−p)·····111/6Kept2025·04
S1.1bBinomial probabilities P(X=r)=nCr p^r (1−p)^{n−r}·1122·64/6Kept2021·06, 2022·12E, 2023·02, 2023·12C, 2024·07, 2024·12C
S1.1cBinomial mean np and variance np(1−p)1·11··33/6Kept2020·12B, 2022·12E, 2023·12C
S1.2aSample proportion p̂ as a random variable·1221175/6Removed2021·14D, 2022·13E, 2022·14D, 2023·02, 2023·11F, 2024·08, 2025·13D
S1.2bNormal approximation to the distribution of p̂11212186/6Removed2020·12B, 2021·14D, 2022·13E, 2022·14D, 2023·11F, 2024·08, 2024·12C, 2025·13D

Most examined dot points by topic

Functions41 hits
  • F1.3a inverse exists / restrict domain — 6 hits, 4 of 6 years
  • F2.2a sums and products of roots — 7 hits, 6 of 6 years
  • F1.3b find f^{−1} — 3; F1.2a–c inequalities rotate as the early algebra item

F1 carries most of the Functions load. Reciprocal and |f| graphs are rare; y^2=f(x) has never appeared. Polynomials show up as remainder/factor in Q11 and as sums of roots later.

Trigonometric Functions40 hits
  • T3a R-method — 6 hits, every year
  • T3b solve a trig equation — 8 hits, 5 of 6 years
  • T1c/T1d inverse-trig identities — the usual inverse-trig MCQ

T2 identities are thin except as a tool for T3 or for ∫sin². t-formulae have never been used. Product-to-sum appeared only as an integrand (2020, 2025).

Calculus64 hits
  • C3.2a direction fields — 8, every year
  • C2a substitution — 9, every year
  • C3.1b volume about the x-axis — 5, every year

C3 dominates the late paper (DE + volume/area). C1 is mostly related rates and cooling. Inverse-trig integrals (C2e) went quiet in 2024–2025.

Vectors47 hits
  • V1.2c dot product / perpendicular — 14 hits, every year
  • V1.1a add/subtract — 6
  • V1.3 projectile — 6 hits across 5 of 6 years

Every paper has an early vector skill and a late vector or projectile item. Projection and geometric proof rotate as the harder vector part.

Combinatorics + Proof27 hits
  • P1a/P1b induction — 6 hits, every year
  • A1.1d combinations — 5; A1.1e pigeonhole — 4 (last chance)
  • A1.2b Pascal identities — 3

One induction is fixed. Counting items rotate through committees, repeated letters, circles and pigeonhole. Straight (a+b)^n expansion is less common than Pascal.

Statistical Analysis25 hits
  • S1.2b normal approximation to p̂ — 8 hits, every year
  • S1.1b binomial probability — 6
  • S1.1a Bernoulli mean/variance — 1 (2025 MCQ)

The z-table p̂ question is the most reliable last-chance item in the course. 2024 drops it for CLT / sampling mean, which cannot appear in 2026.

Recurring question archetypes (same concept, new context each year)

ArchetypeInstancesFrequency
Direction-field MCQ or 1-mark sketch2020 Q7, 2021 Q4 and Q12(a), 2022 Q10 and Q12(a), 2023 Q3, 2024 Q13(a), 2025 Q7Every year
Mathematical induction (sum or divisibility)One induction in every paper 2020–2025 (sums four times, divisibility twice)Every year
Integration by substitution, substitution givenQ11 in 2021, 2022, 2023, 2024; also 2020 Q13(a) and 2025 Q3 / Q12Every year
R-method a sin x + b cos x2020 Q11(d), 2021 Q7, 2022 Q11(e), 2023 Q11(e), 2024 Q10, 2025 Q12(e)6 of 6 years
Normal approximation to the sample proportionAt least one item every year 2020–2025, often a late 3–4 marker with a z-tableEvery year — last chance
Projectile (standard or two-particle)2021 Q13(b), 2022 Q14(c), 2023 Q13(b), 2024 Q14(d), 2025 Q14(b) — absent 20205 of 6 years
Vector perpendicular condition a·b=02020 Q11(b), 2022 Q11(d), 2024 Q12(a), plus MCQ angle/dot items most yearsCore skill
Remainder / factor theorem then factorise2020 Q11(a), 2021 Q3, 2023 Q11(c); multiplicity and sums of roots rotate around it5 of 6 years
Related rates (sphere, tank, sector)2020 Q10, 2021 Q11(e), 2023 Q13(a), 2024 Q11(f), 2025 Q12(a)5 of 6 years
Volume of a solid of revolution2020 Q13(b), 2021 Q13(a), 2022 Q13(b), 2023 Q12(e), 2024 Q12(b), 2025 Q12(b)Every year
Pigeonhole principle2021 Q10, 2022 Q12(b), 2024 Q3, 2025 Q14(a)4 of 6 — last chance
Newton cooling / carrying capacity / logistic2021 Q12(b) and Q14(b), 2022 Q12(d), 2023 Q1, 2024 Q13(a)Rotates with separable DEs

2026 forecast

How to read the tiersTier 1 is the stable core — content examined in five or six of the last six papers. Treat it as near-certain and make it the backbone of your revision. Tier 2 lists dot points that have never, or only once, been examined: 2026 is their last chance under this syllabus, so they are plausible but unproven. Tier 3 is the recency signal — strong history, but skipped in 2025. Tier 4 is content that does not survive into the 2024 Extension 1 syllabus, so 2026 is the only remaining opportunity to examine it. The composite shortlist combines all four signals.

Tier 1 — Bankers: dot points examined 5–6 of 6 years

Dot pointPredicted questionLikely form in 2026Basis
V1.2cPerpendicular condition a·b=0, or an angle from the dot productSolve for a parameterExamined all 6 years (14 hits)
C2a∫ using a given substitutionEvery year; usually Q11Examined all 6 years (9 hits)
C3.2aDirection field: match the DE, or sketch the solution through a pointEvery year, usually MCQ or a 1-mark sketchExamined all 6 years (8 hits)
S1.2bNormal approximation to p̂ with a z-tableLast chance — gone in 2024. Continuity correction sometimesExamined all 6 years (8 hits); last chance (not in 2024 syllabus)
T3bSolve a trig equation on [0,2π] by factorising or a double-angle identityOften the ‘hence’ after R-method or an identityExamined 5 of 6 years (8 hits)
F2.2aSums/products of roots of a cubic or quartic1/α + 1/β + … or α²+β²+γ²Examined all 6 years (7 hits)
S1.2aSample proportion p̂ as a random variableAs in recent papersExamined 5 of 6 years (7 hits); last chance (not in 2024 syllabus)
T3aExpress a sin x + b cos x as R sin(x±α) and solveAlmost every paper; sometimes graph onlyExamined all 6 years (6 hits)
V1.1aAdd/subtract vectors in i, j or column formAlmost every paper, often 1 markExamined 5 of 6 years (6 hits)
C1.3aRelated rates: sphere, tank or sectorGiven dV/dt or dA/dt, find dr/dtExamined 5 of 6 years (5 hits)
C2c(f^{−1})' from f' at the corresponding pointSometimes a second-derivative versionExamined 5 of 6 years (5 hits)
C3.1bVolume of revolution about the x-axisπ∫ y² dxExamined 5 of 6 years (5 hits)
V1.2eProjection of u onto vFormula given or required; last-chance flavour if skippedExamined 5 of 6 years (5 hits)

Tier 2 — Due: never or once examined

Dot pointPredicted questionLikely form in 2026Basis
A1.1aMultiplication principle; arrangements of distinct objects in a lineAs in recent papersNever examined 2020–2025
C1.1aRates with respect to time; 1D particle language ẋ, ẍAs in recent papersNever examined 2020–2025; reduced in 2024
C1.2aExponential growth/decay Q=Ae^{kt}As in recent papersNever examined 2020–2025
C3.2bSolve dy/dx=f(x)As in recent papersNever examined 2020–2025
F1.1bSketch y^2=f(x) and y=√f(x) from y=f(x)As in recent papersNever examined 2020–2025
F2.2cGraph a polynomial from factored form / root multiplicityAs in recent papersNever examined 2020–2025
P1cIdentify errors in false inductions; when induction is not appropriateAs in recent papersNever examined 2020–2025
T2ct-formulae: sin, cos, tan in terms of t=tan(x/2)As in recent papersNever examined 2020–2025; last chance (not in 2024 syllabus)
C3.1cVolume about the y-axis, or the region between two curvesAs in recent papersOnce: 2021·13A
F1.1dSketch y=f(x)+g(x) and y=f(x)−g(x)As in recent papersOnce: 2022·04
F2.1cPolynomial division: P=AQ+R, degree of remainderAs in recent papersOnce: 2022·03
S1.1aBernoulli mean and varianceP(x) table with two outcomesOnce: 2025·04
T2aSum and difference expansions for sin, cos, tanAs in recent papersOnce: 2021·13D
V1.1bGeometric addition/subtraction (triangle or parallelogram law)As in recent papersOnce: 2020·06
V1.2bDirection of a vector; bearings and navigationAs in recent papersOnce: 2021·14A

Tier 3 — Strong history but absent in 2025

Dot pointPredicted questionLikely form in 2026Basis
F1.3aShow an inverse exists (HLT / one-to-one), or restrict the domainOften chained with finding f^{−1} or (f^{−1})'4 of 6 years, 6 hits (2021·12D … 2024·14B)
S1.1bBinomial probability in contextAt least k successes; sometimes expected frequency4 of 6 years, 6 hits (2021·06 … 2024·12C)
A1.1dCommittee / selection using nCrSometimes then a probability4 of 6 years, 5 hits (2020·08 … 2024·09)
F2.1bFactor a cubic given one rootRemainder/factor theorem pair in Q113 of 6 years, 5 hits (2020·05 … 2024·01)
C1.2bNewton's law of cooling or a carrying-capacity modelFind k from two temperatures, then a later time3 of 6 years, 4 hits (2021·12B … 2023·01)
C3.1aArea between curvesSigned pieces; exact value3 of 6 years, 4 hits (2021·13C … 2024·11G)
A1.2aExpand (a+b)^n or find a specified coefficientShort Q11 skill3 of 6 years, 3 hits (2020·14A … 2022·11C)
F1.4aParametric line, parabola or circle → Cartesian, or match a sketchMCQ or 1–2 mark conversion3 of 6 years, 3 hits (2021·08 … 2023·11A)
F2.1aEvaluate P(α) as a remainderShow P(2)=0 then factor3 of 6 years, 3 hits (2020·11A … 2023·11C)
S1.1cBinomial mean np and variance np(1−p)As in recent papers3 of 6 years, 3 hits (2020·12B … 2023·12C)
V1.2gVector proof in a parallelogram, trapezium or circleShow / hence geometric3 of 6 years, 3 hits (2021·14C … 2023·14C); reduced in 2024
V1.3aStandard projectile: time of flight, range or Cartesian pathEquations often given in recent papers3 of 6 years, 3 hits (2021·13B … 2024·14D)

Tier 4 — Last chance: not kept in the 2024 Extension 1 syllabus

Cross-checked against the NESA Mathematics Extension 1 11–12 Syllabus (2024). “Removed” leaves Ext1 (and is not replaced by an Ext1 equivalent). “Reduced” stays in some form but is no longer a named 2017-style item. Ordered by how much examiners have relied on the content since 2020.

Dot pointPredicted questionLikely form in 2026Basis
S1.2bNormal approximation to p̂ with a z-tableLast chance — gone in 2024. Continuity correction sometimesExamined all 6 years (8 hits); last chance (not in 2024 syllabus)
S1.2aSample proportion p̂ as a random variableAs in recent papersExamined 5 of 6 years (7 hits); last chance (not in 2024 syllabus)
A1.1ePigeonhole: minimum n so that at least k are in one groupLast chance — dropped in 20244 of 6 years, 4 hits (2021·10 … 2025·14A); last chance (not in 2024 syllabus)
T2dProduct-to-sum and sum-to-product identitiesAs in recent papers2 of 6 years, 2 hits (2020·12D … 2025·11C); last chance (not in 2024 syllabus)
T2ct-formulae: sin, cos, tan in terms of t=tan(x/2)As in recent papersNever examined 2020–2025; last chance (not in 2024 syllabus)
V1.2gVector proof in a parallelogram, trapezium or circleShow / hence geometric3 of 6 years, 3 hits (2021·14C … 2023·14C); reduced in 2024
C1.1aRates with respect to time; 1D particle language ẋ, ẍAs in recent papersNever examined 2020–2025; reduced in 2024
What the 2024 Ext1 syllabus drops or reduces

Removed: t-formulae (T2c); product-to-sum identities (T2d); pigeonhole principle (A1.1e); the normal approximation to the sample proportion p̂ (S1.2a–b) — 2024 Ext1 explicitly excludes the normal approximation to the binomial and replaces this strand with the sampling distribution of the mean and the central limit theorem.

Reduced: 1D particle language ẋ, ẍ as a standalone Ext1 skill (C1.1a); named vector theorems on parallelograms and midpoints (V1.2g) — 2024 keeps projection and the perpendicular condition, but those geometry proofs are no longer listed.

Reorganised, not dropped: inverse trig moves to Year 12; projectile stays, now grouped with 2D motion in vector form; binomial probabilities stay.

New in 2024 — cannot appear in 2026
  • 3D vectors (i, j, k; magnitude; dot product in three dimensions)
  • 3D trigonometry (moved from Advanced)
  • Graphs of y=sec x, y=cosec x, y=cot x (moved from Advanced)
  • Cubic inequalities in factored form
  • Motion in vector form: r(t), v(t), a(t); Cartesian path of a particle; relative velocity / crosswind
  • Perpendicular component of a vector a − proj_b a as a named formula
  • Sampling distribution of the mean and the central limit theorem (replaces the normal approximation to p̂)
  • Logistic DE solved using a given partial-fraction decomposition

If a practice paper includes 3D vectors, CLT, or sec/cosec/cot graphs as Ext1 content, it is written for the new syllabus and goes beyond what the 2026 exam can ask.

Composite shortlist — candidates with two or more signals

Signals: Core = examined 5–6 of 6 years · Absent 2025 = not in the most recent paper · Untested = 0–1 hits in six papers · Gone 2024 = removed in the 2024 syllabus. Green rows carry three or more signals, blue rows two.

Predicted questionDot pointsCoreAbsent 2025UntestedGone 2024Verdict
Normal approximation to p̂ with a z-tableS1.2bYes——YesStrongest last-chance item: a z-table p̂ question every year since 2020.
Pigeonhole: minimum n so that at least k are in one groupA1.1e———YesFour of six years and leaving the syllabus; a 2–3 mark pigeonhole is very likely.
Product-to-sum and sum-to-product identitiesT2d———YesProduct-to-sum used to integrate (2020, 2025); last chance for the identity itself.
t-formulae: sin, cos, tan in terms of t=tan(x/2)T2c——YesYest-formulae have not appeared in six papers and are dropped in 2024 — plausible one-off.
Direction field: match the DE, or sketch the solution through a pointC3.2aYes———Direction field is a banker; 2025 was only the MCQ, so a sketch part is due.
Standard projectile: time of flight, range or Cartesian pathV1.3a—Yes——Projectile is a late-paper fixture 2021–2025; 2020 skipped it.
Induction on divisibility (usually by 7)P1b————Divisibility induction in 2022 and 2024; 2025 was a sum, so divisibility is due.
Newton's law of cooling or a carrying-capacity modelC1.2b—Yes——Cooling/carrying-capacity absent in 2025 after four earlier appearances.
Sketch y=1/f(x) from a given graphF1.1a————y=1/f(x) only in 2020 and as a graph in 2024 Q12(e); a sketch is overdue.
∫ 1/√(a²−x²) or 1/(a²+x²)C2e————Inverse-trig integral skipped in 2024–2025 after three earlier hits.
Expand (a+b)^n or find a specified coefficientA1.2a—Yes——Straight binomial expansion last in 2022; 2025 used Pascal instead.
Projection of u onto vV1.2eYes———Projection appeared in 2025 as a formula MCQ; a calculation part was last in 2024.
Logistic DE: carrying capacity, max growth rate, sketch on a slope fieldC3.2e————Logistic on a slope field in 2024; not in 2025.
Identify errors in false inductions; when induction is not appropriateP1c——Yes—False-induction / ‘when not appropriate’ has never been examined.
Sketch y^2=f(x) and y=√f(x) from y=f(x)F1.1b——Yes—y^2=f(x) and y=√f(x) have never been examined.
Volume about the y-axis, or the region between two curvesC3.1c——Yes—Volume about the y-axis / between two curves only in 2021.
Sample proportion p̂ as a random variableS1.2aYes——YesSample proportion as a named random variable is leaving with the normal approximation.
A plausible 2026 paper skeleton (10 MCQ + Q11–14, 70 marks)
  • Q11 (a) Vector addition or 2a−b, then a magnitude
  • Q11 (b) Quadratic or rational inequality
  • Q11 (c) Integration by substitution (substitution given)
  • Q11 (d) Remainder/factor theorem, or sums of roots of a cubic
  • Q11 (e) R-method, or differentiate arcsin/arctan of a composite
  • Q11 (f) Related rates (sphere or similar) — or inverse f^{−1}(x)
  • Q12 (a) Direction field: sketch the solution through a given point
  • Q12 (b) Combinations / circular arrangement / binomial coefficient
  • Q12 (c) Induction: a sum, or divisibility by 7
  • Q12 (d) Separable DE with an initial condition
  • Q12 (e) Inverse-trig integral or ∫sin²/cos²
  • Q13 (a) Volume of revolution, or area between curves
  • Q13 (b) Projectile (possibly two particles or an unknown angle)
  • Q13 (c) Vector projection, perpendicular, or a short geometric proof
  • Q14 (a) Logistic DE on a slope field, or a hard separable DE (domain of the solution)
  • Q14 (b) Inverse functions: exist / restrict / (f^{−1})'
  • Q14 (c) Normal approximation to p̂ with a z-table — last chance
  • Q14 (d) Pigeonhole or a Pascal-identity ‘hence’ — last chance; or a trig identity feeding sums of roots

Section I (10 MCQ) is predictable in type: an inequality or inverse, a vector diagram or projection, a direction field, an inverse-trig graph or identity, a binomial/Bernoulli item, a remainder or sums-of-roots item, a substitution or inverse-trig integral, a trig-equation count, a parametric or |f| graph, and one conceptual calculus item.

© Censai 2026. HSC examination papers and syllabuses are © NSW Education Standards Authority; this document references them and does not reproduce examination questions. The Tier 1 core is the backbone of Section II each year; use the lower tiers to round out your revision, not to replace it.