A curve which is the locus of the centers of curvature of another curve (its involute)
- ‘On 22 January 1769 Monge wrote to Bossut explaining that he was writing a work on the evolutes of curves of double curvature.’
- ‘He defines evolutes and involutes of curves and, after giving some elementary properties, finds the evolutes of the cycloid and of the parabola.’
- ‘Of course the evolute of an involute of a circle is a circle.’
- ‘Hence a curve has a unique evolute but infinitely many involutes.’
- ‘He gives propositions determining the centre of curvature which lead immediately to the Cartesian equation of the evolute.’
Mid 18th century: from Latin evolutus, past participle of evolvere ‘roll out’ (see evolve).
We take a look at several popular, though confusing, punctuation marks.