Precalculus and Mathematical Thinking


Expert Definition

Expert-level competence in Precalculus and Mathematical Thinking means you can fluently manipulate all function families (polynomial, rational, exponential, logarithmic, trigonometric), solve competition-grade problems involving trigonometric identities, complex numbers, vectors, and matrices without hints, and recognize which technique applies to novel problems you’ve never seen before. An expert can teach any precalculus topic to another student, derive identities from first principles rather than memorizing them, and tackle problems from competitions like the AMC 12 and AIME that require creative multi-step reasoning. Most importantly, an expert thinks mathematically - they approach unfamiliar problems with structured strategies, not rote pattern-matching.


Resources

Resource 1 (Foundation Builder):

  • Khan Academy — Full Math Path (Pre-Algebra → Algebra 1 → Algebra 2 → Precalculus)

  • Link: khanacademy.org/math/precalculus

  • Type: Interactive platform

  • Cost: Free

  • Format: Self-paced, with videos, articles, practice exercises, unit quizzes, and course challenges

  • Role in stack: Takes you from zero to solid intermediate precalculus

Resource 2 (Expert-Level Mastery):

  • Art of Problem Solving: Precalculus by Richard Rusczyk (Text + Solutions Manual)

  • Link: artofproblemsolving.com/store/book/precalculus

  • Type: Textbook + solutions manual (2-book set)

  • Cost: ~$57 for text, ~$30 for solutions manual (~$87 total); also available as an online book

  • Format: Self-paced; discovery-based pedagogy where each section opens with problems before teaching the theory

  • Role in stack: Takes you from competent intermediate to genuine expert via nearly 1,000 problems ranging from routine to competition-level (AIME/USAMO)

Resource 3 (Video Companion):

  • Professor Leonard — Precalculus: College Algebra & Trigonometry (YouTube Playlist)

  • Link: youtube.com/playlist — Professor Leonard Precalculus

  • Type: Full lecture series

  • Cost: Free

  • Format: Self-paced, 70+ hours of detailed university-style lectures

  • Role in stack: Provides the “classroom experience” — step-by-step worked examples and explanations for when you get stuck on Khan Academy or AoPS problems

Estimated time to expert at 10 hrs/week: ~10–12 months


The Learning Path

Phase 1: Arithmetic & Pre-Algebra Foundations

Resource: Khan Academy — Pre-Algebra course

What you’ll master: Number properties, fractions, decimals, percentages, basic equations, order of operations, negative numbers, exponent basics, intro to variables

Milestone: Pass the Khan Academy Pre-Algebra Course Challenge with 90%+

Duration: ~3 weeks (at 10 hrs/week)

Progress Tracker:

  • Khan Academy — Pre-Algebra course
    • Unit 1: Factors and multiples
      • Factors and multiples (date completed: 07/14/2026)
      • Prime and composite numbers
      • Prime factorization
    • Unit 2: Patterns
    • Unit 3: Ratios and rates
    • Unit 4: Percentages
    • Unit 5: Exponents intro and order of operations
    • Unit 6: Variables & expressions
    • Unit 7: Equations & inequalities introduction
    • Unit 8: Percent & rational number word problems
    • Unit 9: Proportional relationships
    • Unit 10: One-step and two-step equations & inequalities
    • Unit 11: Roots, exponents, & scientific notation
    • Unit 12: Multi-step equations
    • Unit 13: Two-variable equations
    • Unit 14: Functions and linear models
    • Unit 15: Systems of equations
  • Professor Leonard’s prealgebra videos

Phase 2: Algebra 1

Resource: Khan Academy — Algebra 1 course + Professor Leonard’s early algebra videos as needed

What you’ll master: Linear equations and inequalities, systems of equations, quadratic equations, function notation, domain/range, basic graphing

Milestone: Pass the Khan Academy Algebra 1 Course Challenge with 90%+

Duration: ~5 weeks

Progress Tracker:

  • Khan Academy — Algebra 1 course

Phase 3: Algebra 2

Resource: Khan Academy — Algebra 2 course + Professor Leonard videos for tougher topics

What you’ll master: Polynomial operations and factoring, rational expressions, radical expressions, exponential and logarithmic functions, sequences and series, complex numbers (intro)

Milestone: Pass the Khan Academy Algebra 2 Course Challenge with 90%+

Duration: ~6 weeks

Progress Tracker:

  • Khan Academy — Algebra 2 course
  • Khan Academy — College Algebra course

Phase 4: Standard Precalculus

Resource: Khan Academy — Precalculus course + Professor Leonard’s full Precalculus playlist (70+ hours) as lecture companion

What you’ll master: All trig functions and the unit circle, trig identities and equations, vectors, matrices, conic sections, parametric equations, polar coordinates, limits preview

Milestone: Pass the Khan Academy Precalculus Course Challenge with 90%+, then earn the Schoolhouse.world Precalculus Certification

Duration: ~8 weeks

Progress Tracker:

  • Khan Academy — Precalculus course
  • Professor Leonard’s Precalculus videos

Phase 5: Expert-Level Deep Dive

Resource: AoPS Precalculus (Text + Solutions Manual) — work through the full book

What you’ll master: Advanced trigonometry and identities from a problem-solving lens, complex numbers and the geometry of the complex plane, vectors and matrices in 2D and 3D with proofs, competition-level problem-solving strategies, mathematical proof techniques

Method: For each section — attempt all opening problems before reading the text. Work every exercise and review problem. Attempt all challenge problems (use the solutions manual only after genuine effort). The AoPS community forums (free) provide discussion for every problem.

Milestone: Ability to solve AMC 12 and introductory AIME problems involving precalculus topics

Duration: ~16–20 weeks

Total estimated time: ~38–42 weeks (~10 months) at 10 hours/week


Supplementary Resources

AoPS Alcumus (free online problem trainer at artofproblemsolving.com/alcumus) — fills the gap of adaptive, randomized practice that the AoPS textbook doesn’t provide. Alcumus serves precalculus problems at your level, adjusts difficulty based on performance, and is directly aligned with the AoPS curriculum. Use it daily during Phases 4 and 5 for spaced repetition.

AoPS Community Forums (free at artofproblemsolving.com/community) — fills the “community and support” gap of self-study. You can post questions about any AoPS problem, search solutions others have discussed, and engage with a large community of mathematically serious students.