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:
“Isolate city spread alongside water,
Posted with white towers, she keeps her face
Half-turned to Europe, lonely northern daughter,
Holding through centuries her separate place.”
—Philip Larkin (1922–1986)
“In a moment when criticism shows a singular dearth of direction every man has to be a law unto himself in matters of theatre, writing, and painting. While the American Mercury and the new Ford continue to spread a thin varnish of Ritz over the whole United States there is a certain virtue in being unfashionable.”
—John Dos Passos (1896–1970)
“Ah, but to play man number one,
To drive the dagger in his heart,
To lay his brain upon the board
And pick the acrid colors out,
To nail his thought across the door,
Its wings spread wide to rain and snow,
To strike his living hi and ho....”
—Wallace Stevens (1879–1955)