The ratio of the hypotenuse to the shorter side adjacent to an acute angle (in a right-angled triangle); the reciprocal of a cosine.
- ‘He gave a table of secants and, although Delambre credited him with the first use of this function, it had appeared earlier in the work of Copernicus.’
- ‘The secant and cosecant were not used by the early astronomers or surveyors.’
- ‘The secant of this angle is 1.61806 which is remarkably close to the golden ratio 1.618034.’
- ‘It also gave tables of natural sine functions to 15 decimal places, and the tan and sec functions to 10 decimal places.’
- ‘When you move the cursor over a button on the calculator, a description of its function appears - sine of a number, cosine, secant, etc.’
A straight line that cuts a curve in two or more parts.
- ‘In this projection the meridians are vertical and parallels having increased spacing in proportion to the secant of the latitude.’
- ‘Note that the air mass is approximately equal to the secant of the zenith angle (that angle from directly overhead to a line intersecting the sun).’
- ‘Direct irradiance was attenuated as described by Beer's law, with the optical path length increasing approximately as the secant of the solar zenith angle.’
Late 16th century; from French sécante, based on Latin secare ‘to cut’.
We take a look at several popular, though confusing, punctuation marks.