Spread
Spread gives one measure to the 'separation' of two lines (replacing 'angle'): a dimensionless number in the range '0' (parallel) to '1' (perpendicular), which can have several interpretations.
- Trigonometric: as the sine-ratio for the quadrances in a right triangle (and therefore equivalent to the square of the sine of the angle).
- Vector: as a rational function of the slopes (or directions) of two lines where they meet.
- Cartesian: as a rational function of the three co-ordinates used to describe these two vectors.
- Linear algebra: as a normalized rational function of the square of the determinant of two vectors (from three points) divided by the product of their quadrances.
Read more about this topic: Rational Trigonometry
Famous quotes containing the word spread:
“All catches alight
At the spread of spring:
Birds crazed with flight
Branches that fling
Leaves up to the light”
—Philip Larkin (1922–1986)
“Cap off
and then what? The brains as
helpless as oysters in a pint container,
the nerves like phone wires.
God, take care, take infinite care
with the tumor lest it spread like grease.”
—Anne Sexton (1928–1974)
“[Allegory] should ... be very sparingly practised, lest, whilst the writer plays with his own fancies and diverts himself by cutting the air with his wide spread wings, he should soar out of view of his readers, leaving them in confusion and perplexity to explore his viewless track.”
—Sarah Fielding (1710–1768)