Calculo
Interactive Calculus

See calculus move.

Calculus is the mathematics of change. Instead of memorizing rules, drag a point, slide a value, and watch the ideas — slope, area, and the limit — unfold in front of you.

Open the derivative lab A growing set of hands-on explorers. No sign-up, nothing to install.
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Derivative & Tangent Line

Slide a point along a curve and watch the tangent's slope trace out the whole derivative f′(x).

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Area Under the Curve

Add rectangles one by one — Riemann sums — and see them squeeze toward the exact integral.

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Limits & Continuity

Walk toward a point from both sides and see what value the function is really approaching.

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Taylor Approximation

Add polynomial terms one at a time and watch them curl into the shape of the true curve.

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The Accumulation Function

Sweep the upper limit and watch the running-area curve draw itself — its slope is exactly f(x).

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Maxima & Minima

Hunt down every peak and valley, and let the second-derivative test name each one.

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Slope Fields

Read a differential equation as a field of tangents, then thread a solution curve through it.

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Newton’s Method

Chase a root down the tangent lines and watch the guess double its accuracy every step.

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Volume by Disks

Spin a curve into a solid and stack disks until the sum becomes the exact volume, π∫f².

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Mean Value Theorem

Between any two points, a tangent must run parallel to the chord — find the guaranteed spot.

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Related Rates

Slide a ladder at steady speed and watch the top race away — rates chained by the equation.

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Infinite Series

Add up endless terms and watch the partial sums settle on a number — or wander off forever.

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Parametric & Polar

Drive both coordinates by a clock and trace loops, spirals, and flowers a function can't.

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Epsilon & Delta

Play the rigorous-limit game: name a tolerance and find the window that keeps the curve inside.

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Area Between Curves

Trap a region between two graphs and sum the gap — top minus bottom — into its area.

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Arc Length

Straighten a curve with a chain of tiny segments until the total becomes ∫√(1+f′²).

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The Chain Rule

Follow x through a two-stage pipeline and watch the rates at each stage multiply.

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L’Hopital’s Rule

Crack a 0/0 limit by swapping the ratio of curves for the ratio of their tangent slopes.

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The Shell Method

Rotate about the y-axis and build the solid from nested shells: 2π∫x·f(x)dx.

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Polar Area

Fan triangular wedges from the origin to sweep out a polar region: ½∫r²dθ.

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Average Value

Find the rectangle with the same area as the curve — and the point where f hits that height.

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Implicit Differentiation

Find the tangent slope on a curve that isn't a function: dy/dx = −Fx/Fy.

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Improper Integrals

Push the boundary to infinity and see whether an endless region holds a finite area.

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Change, made visible
Every explorer turns an abstract symbol into something you can move. The derivative isn't a formula to recall — it's the slope you're watching tilt in real time.
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Play, then understand
Drag first, read the numbers second. When the tangent goes flat exactly where the curve peaks, the meaning of f′(x)=0 lands on its own.
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Built for the classroom
A companion to Knovay's GeoProof (geometry) and Physica (physics) — the same clean, distraction-free style, ready to project or hand to a student.