Tools
CAS / calculus
Tangents and rates of change — before the formal rules.
Overview
A derivative is an instantaneous rate; geometrically it is the tangent slope. Move the point of tangency and watch the line rotate.
Teaching tip
Slow down near extrema: the tangent flattens and the slope approaches 0.
Resources in this tool
FAQ
Do students need differentiation rules first?
Use this as geometric motivation; practice algebraic rules afterward.
Is this tool free?
Yes. It runs in the browser with no install.
Good for class demos?
Yes — project it and ask what changes when you drag a parameter.
How do I write the formula afterward?
Open the equation editor or symbol sheet and copy a clean expression.