Shapes & spaces

Tangent line at a circle point calculator

Find the implicit equation of the tangent to a circle at a given point.

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Behind the numbers

How this calculation works

Find the implicit equation of the tangent to a circle at a given point.

THE FORMULA(x₀−h)(x−x₀)+(y₀−k)(y−y₀)=0

A worked example

For centre (1,1) and point (4,5), the tangent is 3x+4y−32=0.

Good to know

The given point must differ from the centre.

Read the result

Find the implicit equation of the tangent to a circle at a given point.

The primary result is labeled “Normal x coefficient”. Keep the input definitions in view when comparing this result with another method.

Try a related calculation

The given point must differ from the centre.

For a related exercise, try the circle calculator.

A few questions, answered

How can I check the default inputs by hand?

For centre (1,1) and point (4,5), the tangent is 3x+4y−32=0.

Which rule does this calculator apply?

(x₀−h)(x−x₀)+(y₀−k)(y−y₀)=0

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