Leaving Certificate · Higher Level · Paper 1 · Strand 4

Stop practisingthe algebra you can already do.

Algebra & Complex Numbers is 66 short, guided lessons built around the question types that keep coming back. First you see the method. Then you try it. Then the help comes away.

This is Strand 4 of five, not the whole course. The other strands are still being written. Your purchase includes one year's access to Algebra & Complex Numbers only.

66guided lessons
Strand 4sold on its own
1 yearof access

Peter O'Hagan · teaching for over 20 years

Today's plan18–24 min

The Factor Theorem · Lesson 12

Turn a cubic into a route you already know.

Lesson progress3 of 5 steps
Up nextWorked example → guided attempt

CourseAlgebra & Complex Numbers

LevelLeaving Certificate Higher Level

FormatGuided self-study in the Forkhill app

Revision should expose the gap

Practise the question you need—not the one you already know.

Familiar questions make revision feel productive. They do not show you what will catch you out in the exam. The course gives you a deliberate route through these recurring question types.

01

Rearrange, factorise and simplify the algebra the rest of Paper 1 depends on

02

Solve polynomial equations of degree 3 and higher, with or without a factor given

03

Recognise hidden quadratics and handle equations containing a square root

04

Solve simultaneous equations, including three unknowns and mixed-order pairs

05

Solve inequalities, including modulus and denominator cases

06

Move between rectangular and polar form and apply De Moivre’s theorem

Five stages in every lesson

Shown properly. Then the help comes away.

Every lesson begins with the working on show and ends with you applying the method somewhere less familiar. If you need help, hints arrive one at a time, so you get a nudge before you get the answer.

The app is where you find out whether you were right. The paper is where you do the working—and where the marks are earned.
ExplainModelImitateFadeApply
Read the four-minute app guide
01 · Today's plan12 min

A focused next step

Return to inequalities with an unknown in the denominator.

02 · Guided attemptOn paper

Method mark earned. Now test the sign in each interval.

03 · Spaced returnScheduled

The question returns before the method has time to disappear.

04 · Mistake notebookPrivate to you

“I forgot to test which intervals made the expression positive.”

One honest sentence is more useful than re-reading the whole lesson later.

01

Explain

Learn the method through one example worked all the way through.

02

Model

Watch it used on a real question, from the first line to the last.

03

Imitate

Take the same steps yourself before you reveal the working.

04

Fade

Try again with fewer prompts and more of the method left to you.

05

Apply

Use it in the less obvious form you are more likely to meet in an exam.

What's covered

The algebra Paper 1 keeps asking for.

Algebra comes first in the story because it supports so much of the paper. Complex numbers remains part of the strand, but the sequence is built around the algebraic fluency students repeatedly need.

01

Polynomial thinking

Build the habits that make higher-degree equations feel structured rather than improvised.

  • The Factor Theorem
  • Polynomial equations of degree 3 and higher
  • Conditions on the roots of a quadratic
02

Algebraic fluency

Strengthen the manipulation that sits underneath almost every successful Paper 1 solution.

  • Rewriting expressions and surds
  • The binomial theorem
  • Hidden quadratics and equations with a square root
03

Equations & inequalities

Build a dependable route through the cases where signs, roots and unknowns can catch you out.

  • Three simultaneous unknowns
  • One linear and one order-2 equation
  • Modulus and denominator inequalities
04

Complex numbers

Connect each representation so you can choose the one the question actually needs.

  • Rectangular and polar form
  • De Moivre’s theorem
  • Roots of a complex number and proofs

The app checks. You do the maths.

Work it on paper.Use the feedback well.

Where partial credit applies, you can see which parts earned marks. The app does not pretend to replace handwritten exam working; it helps you practise it more deliberately.

01

A useful next step

Today’s Plan suggests what to work on next. It is advice, not a gate, and every lesson remains open from day one.

02

Bring it back before it fades

Practice & Review returns questions after a gap so ‘I could follow that’ has a chance to become ‘I can do that’.

03

Your mistakes, in your words

Keep a private note of what caught you out and build revision around your mistakes rather than everybody else’s.

04

Working still happens on paper

Read the question on screen, work it as you would in the exam, then enter your answer and compare the method. Printable sheets help keep that working clear.

Built and taught by Peter O'Hagan

Professional teaching judgement, built into every next step.

I have spent 23 years teaching and preparing students for high-stakes examinations, including 21 years in a Northern Ireland grammar school and time as Head of Physics. I now teach Leaving Certificate Maths and Physics in the Republic of Ireland.

This course turns that classroom judgement into a clearer self-study route: diagnose the question, sequence the practice, revisit it before it fades and move towards independent exam working.

BSc (Hons)Physics with AstrophysicsMaster's with DistinctionEducational StudiesFormerHead of Physics

Straightforward scope and pricing

Start with the strand that makes the rest of Paper 1 easier to handle.

Algebra & Complex Numbers is sold as its own complete strand. You can see exactly what is included before you pay, with no suggestion that this is the full Higher Level Maths course.

Founding-student credit

Buy at €39 now and receive a €39 credit if you later buy the completed multi-strand course, if and when it becomes available.

Founding price

39

First 30 students or until 30 September 2026. €49 thereafter.

  • 66 guided Algebra & Complex Numbers lessons
  • One year's access
  • Today's Plan, feedback and spaced review
  • Printable working sheets
Start this course for €39

Immediate digital access requires your express agreement before payment. A parent or guardian must arrange payment for a student under 18.

Questions, answered clearly

Before you begin.

No vague bundles and no implied future access. Here is what this purchase means.

Is this the full Leaving Certificate Higher Level Maths course?

No. This purchase is for the standalone Algebra & Complex Numbers strand only. Other strands are still being written and will be priced separately if and when they are released.

What do I get access to?

You receive one year’s access to 66 guided lessons, question practice, feedback, spaced review, the mistake notebook and printable working sheets for Algebra & Complex Numbers.

How does the €39 founding price work?

The founding price is €39 for the first 30 students or until 30 September 2026, whichever comes first. The price is then €49.

What happens if a complete multi-strand course is released later?

Students who buy this strand at the €39 founding price will receive a €39 credit if they later buy the completed multi-strand course, if and when it becomes available.

Do I need anything beside the app?

Bring a pen and paper. The app is designed to guide real exam-style working, not to be tapped through like a quick quiz.

Can a student under 18 buy the course?

A parent or guardian must set up the account and arrange payment for a student under 18.

Right work. Right order. Right time.

Know how to start the next algebra question.

You do not need another pile of questions. You need a clear next one—and a method you can still use when the numbers change.

Start the course — €39

One year's access · founding price terms apply