Tan or TAN may refer to:

Common meanings

Tanning

Biology

Geography

History

The Japanese language uses a broad array of honorific suffixes for addressing or referring to people. These honorifics attach to the end of people's names, as in Aman-san where the honorific -san was attached to the name Aman. These honorifics are often gender-neutral, but some imply a more feminine context (such as -chan) while others imply a more masculine one (such as -kun).

These honorifics are often used along with other forms of Japanese honorific speech, keigo, such as that used in conjugating verbs.

Usage

Although honorifics are not part of the basic grammar of the Japanese language, they are a fundamental part of the sociolinguistics of Japanese, and proper use is essential to proficient and appropriate speech. Significantly, referring to oneself using an honorific, or dropping an honorific when it is required, is a serious faux pas, in either case coming across as clumsy or arrogant.

They can be applied to either the first or last name depending on which is given. In situations where both the first and last names are spoken, the suffix is attached to whichever comes last in the word order.

In mathematics, the trigonometric functions (also called the circular functions) are functions of an angle. They relate the angles of a triangle to the lengths of its sides. Trigonometric functions are important in the study of triangles and modeling periodic phenomena, among many other applications.

The most familiar trigonometric functions are the sine, cosine, and tangent. In the context of the standard unit circle (a circle with radius 1 unit), where a triangle is formed by a ray originating at the origin and making some angle with the x-axis, the sine of the angle gives the length of the y-component (the opposite to the angle or the rise) of the triangle, the cosine gives the length of the x-component (the adjacent of the angle or the run), and the tangent function gives the slope (y-component divided by the x-component). More precise definitions are detailed below. Trigonometric functions are commonly defined as ratios of two sides of a right triangle containing the angle, and can equivalently be defined as the lengths of various line segments from a unit circle. More modern definitions express them as infinite series or as solutions of certain differential equations, allowing their extension to arbitrary positive and negative values and even to complex numbers.