👉 Sec (Secant) is a trigonometric function that represents the ratio of the length of a secant segment to its adjacent side in a right triangle. Specifically, if \( \theta \) is an angle in a right triangle with adjacent side length \( a \) and opposite side length \( b \), the secant of \( \theta \), denoted \( \sec(\theta) \), is defined as \( \sec(\theta) = \frac{1}{\cos(\theta)} \). This function is the reciprocal of cosine, meaning \( \sec(\theta) = \frac{1}{\cos(\theta)} \). Unlike sine and cosine, which vary between -1 and 1, secant can take any real value except zero, making it useful in various applications, including physics and engineering, where it often appears in problems involving periodic phenomena or when dealing with angles that are not standard (like 0° or 180°).
