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:
“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)
“The philanthropist too often surrounds mankind with the remembrance of his own cast- off griefs as an atmosphere, and calls it sympathy. We should impart our courage, and not our despair, our health and ease, and not our disease, and take care that this does not spread by contagion.”
—Henry David Thoreau (1817–1862)
“A little quaker, the whole body of him trembling,
His absurd whiskers sticking out like a cartoon-mouse,
His feet like small leaves,
Little lizard-feet,
Whitish and spread wide when he tried to struggle away,”
—Theodore Roethke (1908–1963)