cotangent
/'kou'tændʤənt/
Học thuậtThân thiện
Definition
- Noun:
- A trigonometric function: The cotangent is a trigonometric function defined for an angle in a right-angled triangle as the ratio of the length of the adjacent side to the length of the opposite side. It is the reciprocal of the tangent function.
Usage
- The cotangent is used in mathematics, particularly in trigonometry, geometry, and calculus.
- It is commonly abbreviated as cot.
- It is applied to solve problems involving angles and side lengths in triangles, wave functions, and oscillatory phenomena.
Examples
- Noun:
- In a right triangle with an angle θ, the cotangent of θ is calculated as adjacent/opposite.
- The value of the cotangent function decreases from infinity to zero as the angle increases from 0 to 90 degrees.
- To find the unknown side, we used the cotangent of the known angle.
Advanced Usage
- Mathematical Identity: The cotangent can be expressed in terms of other trigonometric functions: cot(θ) = cos(θ) / sin(θ) = 1 / tan(θ).
- Inverse Function: The inverse cotangent function, written as arccot(x) or cot⁻¹(x), returns the angle whose cotangent is x.
- Calculus: The derivative of cot(x) is -csc²(x), and its integral is ln|sin(x)| + C.
Variants and Related Words
- Cot (abbr.): The standard abbreviation for cotangent.
- Calculate cot(45°).
- Cotangential (adj.): Pertaining to or involving the cotangent.
- The cotangential relationship was key to the proof.
Synonyms
- Reciprocal tangent: This phrase describes the fundamental relationship, as cotangent is the multiplicative inverse (reciprocal) of the tangent function.
Related Phrases
- Cotangent bundle (n.): A mathematical construct in differential geometry formed from a manifold and the cotangent spaces at each point.
- The physics problem was analyzed using the cotangent bundle.
- Hyperbolic cotangent (n.): A related function, denoted coth, defined for hyperbolic trigonometry.
- The hyperbolic cotangent is defined as coth(x) = cosh(x) / sinh(x).
Noun
- ratio of the adjacent to the opposite side of a right-angled triangle