How is the secant (sec) function expressed in terms of cosine?

The secant function is defined as the reciprocal of the cosine function. Consequently, the secant of an angle is equal to 1 divided by the cosine of that angle. This relationship can be derived from the definitions of the trigonometric functions in the context of a right triangle or the unit circle. In mathematical terms, if we say that sec(θ) = 1/cos(θ), we capture the essence of how secant connects directly back to cosine.

This fundamental relationship is essential in trigonometry, and recognizing that sec(θ) and cos(θ) are directly related through this reciprocal relationship is crucial for solving various problems in the subject. Understanding this relationship not only aids in simplifying expressions involving secant but also in solving equations that include trigonometric functions.