# Intrinsic equations

- Author:
- Integral Resources

- Topic:
- Equations

Use the vertical slider to choose a curve.
The arc length from a fixed point is s (shown in red) and the angle which the tangent makes with the horizontal is ψ. Use the horizontal slider to move the point around the curve, and see how s and ψ change.
The curvature at the point is also shown. Look at how this varies as you move the point round.