Calculus Calculators
Tangent Line Calculator
Find the tangent line to a curve at a point and plot it.
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What is Tangent Line?
The tangent line touches a curve at a point and has the same slope there, which is exactly f′(a). It is the straight-line approximation the derivative gives you, and the reason the derivative is described as the slope of the curve.
How it works
The derivative is evaluated at a for the slope, the function for the point, and the two are combined into the tangent equation, which is then drawn over the curve. Seeing the line agree with the curve at the point and diverge elsewhere is the whole idea of a local linear approximation.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.