Explainers
Each explainer starts with a short answer. Then a step-by-step animation shows how it works, at your own pace. Worked examples, common mistakes and a quiz come after.
What a hypothesis test and a p-value are, how the significance level decides and which mistakes to avoid - with an animated blind tasting test, a lab, examples and a quiz.
19 min read
How to integrate a product and a composite function - integration by parts and by substitution as derivative rules run in reverse, with an animation, an interactive graph, worked examples and a quiz.
13 min read
What it means for a sequence or a function to have a limit - with an animation of a narrowing ε band, an interactive ε-δ graph, worked examples, common mistakes and a quiz.
15 min read
How a 2 × 2 matrix moves the plane, why its columns show where e₁ and e₂ go and what the determinant tells you - with an animated grid, a matrix lab, examples and a quiz.
16 min read
What the normal distribution and the standard deviation are, where the 68-95-99.7 rule comes from and how to use z-scores - with an animated histogram, a lab, examples and a quiz.
16 min read
What a definite integral is and where F(b) − F(a) comes from - with an animation of rectangles filling the area under a graph ever more closely, worked examples and a quiz.
9 min read
What a derivative is, where it comes from and how to work it out - with an animation of a secant turning into a tangent, worked examples and a quiz.
10 min read
How mitosis works, how meiosis works and why they differ - with animations of every phase, a gamete lab, worked examples and a quiz.
12 min read