Onlock · Interactive course

Learn Calculus 1 & AP Calculus AB by doing

Onlock is a complete, interactive Calculus 1 course. Every topic is a ladder of exam-style questions you solve yourself - dragging tangent lines, building the product rule from pieces, reading limits off real graphs - with instant hints when you get stuck and a video before each level that teaches exactly the move you are about to use.

The syllabus follows AP Calculus AB, and it works just as well for a university Calculus 1 class: the maths is the same limits, continuity and derivatives, taught without assuming any exam board.

Start practising free

Unit 1: Limits and Continuity

11 topics, from evaluating limits by substitution to the Intermediate Value Theorem. Every level is live.

  • ·Limits by substitution - 5 levels of practice
  • ·Limits from graphs - 4 levels of practice
  • ·One-sided limits - 5 levels of practice
  • ·Infinite limits - 6 levels of practice
  • ·Limit laws - 5 levels of practice
  • ·Continuity at a point - 6 levels of practice
  • ·Removable discontinuities - 5 levels of practice
  • ·Continuity over an interval - 5 levels of practice
  • ·Intermediate Value Theorem - 5 levels of practice
  • ·Sandwich Squeeze Theorem - 5 levels of practice
  • ·Change at an instant - 3 levels of practice

Unit 2: Differentiation

What a derivative is, where it exists, and every rule for finding one - each rule built by hand before it is practised.

  • ·What is a derivative? - 8 levels of practice
  • ·The limit definition - rolling out now
  • ·Differentiability & continuity - rolling out now
  • ·Power rule - rolling out now
  • ·sin, cos, eˣ & ln x - rolling out now
  • ·Product rule - rolling out now
  • ·Quotient rule - rolling out now
  • ·tan, cot, sec & csc - rolling out now
  • ·Chain rule - rolling out now
  • ·Implicit differentiation - rolling out now
  • ·Inverse function derivatives - rolling out now
  • ·Higher-order derivatives - rolling out now

How Onlock teaches calculus

Solve, don't watch. Lectures feel like progress and evaporate by the exam. On Onlock you answer a question every few seconds: tap the chips that build the quotient rule, type the derivative, drag the point that defines the tangent line. Mistakes shake, hints are one tap away, and nothing moves on until you have actually done the move.

One new move per level. Each topic is split into short levels that teach exactly one skill - spot the inside function, then differentiate the outside, then multiply. You always know what a level is for, and the question you get wrong tells you precisely which move to fix.

Exam-style from day one. The questions mirror how AP Calculus AB and university Calculus 1 exams actually ask things - graphs, tables, and expressions, never trivia. Finish a topic and its readiness test tells you if you would score full marks on it today.

Who it's for

AP Calculus AB students, university students taking Calculus 1, and anyone relearning limits and derivatives from scratch. It is free to start: every topic opens with free levels, and there is a free daily calculus question you can try without an account.

Start now

Jump into the first limits level - no card, no setup, straight into a question.

Try Onlock free