Mathematics Extension 1
E1
HSC · HSC Year 12 · syllabus

HSC Mathematics Extension 1 syllabusmodules explained

Mathematics Extension 1 is taken on top of Mathematics Advanced and adds vectors, combinatorics, formal proof by induction and a harder layer of calculus, including differential equations and projectile motion. The examination rewards structured reasoning: most long-response parts ask you to establish a stated result or build a model, so the marks attach to a justified chain of working rather than to a final answer alone.

Mathematics Extension 1 Stage 6 Syllabus (2017), examined from 2020 to 2026

Extension 1 is examined in one written paper each year, released by NESA with marking guidelines and, more recently, marking feedback covering Section II. In the questions mapped in our bank the paper opens with one-mark multiple-choice items running to Q10, then moves to multi-part questions numbered from Q11 in which individual parts have carried anywhere from one to seven marks. Those parts usually escalate within a question, starting from a routine technique and ending in an unfamiliar application or a proof.

Past papers on this subject span more than one syllabus. Papers written under an older one still work as practice, but the modules they test have changed — the index labels every paper with the syllabus it was set under.

Pre-2017 syllabus (3 Unit era Extension 1 course) · 20152019Mathematics Extension 1 Stage 6 Syllabus (2017) · 20202026Mathematics Extension 1 11-12 Syllabus (2024) · 2027present

The modules, one by one

Each area below lists the concepts named in the syllabus, what the NESA exam asks of them, and the mistake that most often costs marks.

Area 1 of 7

Functions

This topic pushes the Advanced work on functions into territory where you reason about a graph you have never plotted. You work with reciprocals of functions, square roots of functions and absolute value graphs, deducing asymptotes, turning points and where a transformed curve must sit from the behaviour of the original. Inequalities are treated properly here: rational inequalities with a variable in the denominator, inequalities involving absolute values, and inequalities solved by graphing two functions and reading off the region. Parametric representation of curves appears, including converting between parametric and Cartesian form. The polynomials strand covers division, the remainder and factor theorems, multiplicity of roots and their graphical meaning, and the relationships between the coefficients of a polynomial and the sums and products of its roots. Those root relationships turn up repeatedly in later questions, so the algebra here is worth being fast at.

What the syllabus lists under this area · 2 points
  • Further work with functions
  • Polynomials

What the exam asks

Expect short items that ask you to solve an inequality exactly or sketch a transformed curve with asymptotes and intercepts labelled, and polynomial parts that use root-coefficient relationships rather than solving. Mapped 2025 questions use the roots of a cubic to evaluate a symmetric expression and, in a harder part, to pin down an angle sum from roots written as tangents.

Where marks go missing

Multiplying both sides of a rational inequality by the denominator without knowing its sign. Multiply by the square of the denominator, or test intervals, and always exclude the value that makes the denominator zero from the final solution set.

Area 2 of 7

Trigonometric Functions

The inverse trigonometric functions are defined here as genuine functions, which means committing their restricted domains and ranges to memory and being able to sketch the graphs of arcsin, arccos and arctan, including their symmetry properties and derivatives. Alongside that sits the identity work: sums and differences of angles, double and triple angle results, products expressed as sums, the t-formulae, and rewriting a cos x + b sin x as a single sine or cosine with an auxiliary angle. Those tools then feed the equation solving, where you solve trigonometric equations exactly over a restricted domain, or give general solutions covering every period. Applications include modelling periodic situations, so you also need to move between an angle in a diagram and a time in a model.

What the syllabus lists under this area · 3 points
  • Inverse trigonometric functions
  • Further trigonometric identities
  • Trigonometric equations

What the exam asks

Questions run from one-mark multiple-choice items on general solutions to three-mark parts that solve an equation using a double-angle identity over a stated domain, differentiate a composite of inverse and ordinary trigonometric functions on a restricted domain, or model a rotating system such as clock hands and find the first two times a condition is met.

Where marks go missing

Losing solutions when you cancel. Dividing an equation by cos x or sin x deletes the roots where that factor is zero, and a restricted-domain question is marked on the complete solution set, not just the first value your calculator returns.

5 real NESA questions indexed on this area →

Area 3 of 7

Calculus

Three strands sit here. Rates of change covers related rates, where two quantities are linked by a geometric or physical relationship and you differentiate that relationship with respect to time, and exponential models of the form where a quantity approaches a limiting value. Further calculus skills add integration by substitution, integrals producing inverse trigonometric functions, integrating squared sine and cosine using double-angle identities, and differentiating inverse functions. Further applications brings differential equations: sketching and interpreting direction fields, and solving separable equations, including logistic-style models, with an initial condition to fix the constant. Projectile motion is treated in this course as an application of calculus and vectors, so you derive the equations of motion rather than quoting them, and volumes of revolution round out the integration work.

What the syllabus lists under this area · 3 points
  • Rates of change
  • Further calculus skills
  • Further applications of calculus

What the exam asks

Related-rates parts are typically worth three to six marks and require the relationship written down before differentiating; differential equation parts ask you to separate, integrate and apply the initial condition. Mapped questions include a sector with constant area, a leaking conical container, a reaction-rate model, and a two-particle projectile problem set up as a 'show that'.

Where marks go missing

Substituting the given numerical value before differentiating in a related-rates question. The radius or height has to stay a variable until after the derivative is formed; substitute the instantaneous value only at the final step, or the derivative collapses.

8 real NESA questions indexed on this area →

Area 4 of 7

Combinatorics

Counting is done from principles rather than formulas here. You use the multiplication principle for arrangements, then handle the standard complications: arrangements with restrictions, objects that must or must not be adjacent, identical objects, and arrangements in a circle where one position is fixed to remove rotational duplicates. Combinations follow, with selections subject to composition constraints and the use of complementary counting when a condition reads 'at least one'. The pigeonhole principle appears as a proof tool. The binomial theorem strand covers expanding a binomial power, finding a particular term or coefficient, and the identities that come out of Pascal's triangle, including the recurrence linking adjacent coefficients. Proving identities by manipulating those coefficients, or by differentiating or substituting into the expansion, is a regular feature.

What the syllabus lists under this area · 2 points
  • Permutations and combinations
  • The binomial theorem

What the exam asks

Short parts ask for a count under a restriction, such as circular seating where two guests must be separated. Harder parts ask you to prove a binomial-coefficient identity, either by telescoping with the Pascal's triangle recurrence or by deriving two standard identities from the expansion and combining them. Multiple-choice items test at-least-one selections.

Where marks go missing

Adding overlapping cases when the condition is 'at least one'. Counting the arrangements containing exactly one, then exactly two, and summing them double-counts unless the cases are genuinely disjoint; subtracting from the unrestricted total is usually safer.

4 real NESA questions indexed on this area →

Area 5 of 7

Proof

Mathematical induction is the named subtopic, and the course expects the full formal structure every time: verify the base case, state the assumption for n equal to k clearly, then prove the statement for k plus one using that assumption, and close with a concluding statement invoking the principle of induction. Induction is applied to summation identities, divisibility results, inequalities and expressions involving factorials or products. The wider proof work in the course also asks you to argue directly rather than compute, using algebraic manipulation, counter-examples, and results about divisibility and factors of integers. Because a proof question tells you what to prove, no marks are available for a correct answer alone; every mark sits in the visible steps, particularly in the line where the assumption is actually used.

What the syllabus lists under this area · 1 point
  • Proof by mathematical induction

What the exam asks

A three-mark induction part is standard, often on a summation identity involving factorials, and sometimes preceded by an algebraic step such as factorising a cubic that is then used in the inductive step. Divisibility proofs appear as shorter parts. Marks are attached to stating the assumption and to the point where it is substituted.

Where marks go missing

Working the k plus one case forward without ever invoking the assumption. If your working would be valid with the assumption deleted, you have verified an identity rather than proved it, and the mark for using the assumption is lost.

8 real NESA questions indexed on this area →

Area 6 of 7

Vectors

Vectors are new to this course and are examined heavily. You represent vectors in component and column form, add and subtract them, multiply by scalars, find magnitude and direction, and use unit vectors. The scalar (dot) product gives the angle between two vectors, tests for perpendicularity, and produces the projection of one vector onto another, which is the single most-used construction in the topic. Position vectors let you express geometric conditions algebraically, so collinearity, parallelism and ratios of division along a line all become vector equations, and standard plane geometry results can be proved this way. The further work applies calculus to vectors: differentiating a position vector to get velocity and acceleration, and analysing motion, including projectile motion, in vector form rather than as separate horizontal and vertical equations.

What the syllabus lists under this area · 2 points
  • Introduction to vectors
  • Further work with vectors

What the exam asks

Multiple-choice items ask for a projection, for the condition satisfied by three collinear position vectors, or for an angle deduced from a vector sum equal to zero. Longer parts give a vector-valued position function and ask for the time at which velocity and acceleration meet a stated angle, which requires differentiating twice and then using the dot product.

Where marks go missing

Confusing the scalar projection with the vector projection, and dividing by the wrong magnitude. The projection of a onto b is scaled by the magnitude of b, not of a; getting that the wrong way round produces a plausible number that earns nothing.

5 real NESA questions indexed on this area →

Area 7 of 7

Statistical Analysis

This topic formalises randomness. Bernoulli trials come first, with a single trial's mean and variance, then the binomial distribution: the probability of a given number of successes, the mean np, the variance np times one minus p, and the shape of the distribution as n and p change. You then move to the normal approximation to the binomial, using continuity where appropriate and standardising to z-scores to estimate probabilities that would be impractical to sum. The sampling distribution of the sample mean follows: how the mean of samples drawn from a population is itself distributed, why its spread is smaller than the population's, and how the standard deviation of that distribution depends on sample size. The practical outcome is being able to reason about how likely a sample result is under an assumed model.

What the syllabus lists under this area · 2 points
  • The binomial distribution
  • The sampling distribution of the mean

What the exam asks

A one-mark item may ask for the mean and variance of a Bernoulli or binomial variable straight from a given probability function. A four-mark part is more typical of the harder work: using a normal approximation with a stated mean and a given tail probability to solve backwards for an unknown threshold value.

Where marks go missing

Using the population standard deviation where the standard deviation of the sample mean is required. The spread of a sample mean shrinks with sample size, so standardising with the unscaled figure gives a z-score that is too small and a wildly wrong probability.

2 real NESA questions indexed on this area →

Common questions

Which syllabus does the HSC Mathematics Extension 1 exam follow?

HSC papers from 2020 to 2026 are set on the Mathematics Extension 1 Stage 6 Syllabus published in 2017. A new Mathematics Extension 1 11-12 Syllabus applies from 2027. Papers before 2020 come from the earlier 3 Unit era course, which shared some content but organised it differently.

Are pre-2020 Extension 1 past papers still worth doing?

Selectively. Induction, combinatorics, related rates and differential equation questions transfer well. Skip the old simple harmonic motion, circle geometry proof and parabola locus questions that appear in papers up to 2019, since those strands are not part of the current syllabus and no equivalent question can appear in your exam.

What topics are in HSC Mathematics Extension 1?

Seven: Functions, Trigonometric Functions, Calculus, Combinatorics, Proof, Vectors and Statistical Analysis. Vectors and formal proof by induction carry a lot of exam weight, and projectile motion is examined as an application of calculus and vectors rather than as a topic of its own.

Does the Extension 1 exam assume Mathematics Advanced content?

Yes. Extension 1 is studied alongside Advanced, not instead of it, and Extension 1 questions freely use Advanced techniques such as differentiation rules, logarithms, integration and the normal distribution. A question can be set entirely on Extension 1 content while still requiring fluent Advanced algebra to reach the answer.

Practise it against the real thing

Knowing the syllabus is the first half. The other half is seeing how NESA actually asks it — every official paper for Mathematics Extension 1 is indexed by the same areas above.

Past papers by topic →Mathematics Extension 1 practice exams →