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:
“Everywhere, spread all over in characters of living light, blazing on all its ample folds, as they float over the sea and over the land, and in every wind under the whole heavens, that other sentiment, dear to every true American heart,—Liberty and Union, now and for ever; one and inseparable!”
—Daniel Webster (1782–1852)
“All catches alight
At the spread of spring:
Birds crazed with flight
Branches that fling
Leaves up to the light”
—Philip Larkin (1922–1986)
“I could have spread my wings and done a thousand things I’ve never done before.”
—Alan Jay Lerner (1918–1986)