arcsecant
Học thuậtThân thiện
Definition
- Noun:
- The inverse function of the secant: In trigonometry, the arcsecant is the inverse function of the secant. For a given number x where |x| ≥ 1, the arcsecant of x is the angle (typically measured in radians) whose secant is x. It returns an angle in the range [0, π] excluding π/2.
Usage
- The arcsecant function is used to find an angle when the value of the secant of that angle is known.
- It is denoted as arcsec(x) or sec⁻¹(x).
- The input value () must satisfy || ≥ 1 because the secant of an angle is never between -1 and 1.
Examples
- Noun:
- To solve the equation sec(θ) = 2, we calculate θ = arcsec(2).
- The value of arcsecant(-√2) is 3π/4 radians.
- The derivative of the arcsecant function is an important result in calculus.
Advanced Usage
- Principal Value: The principal value of is conventionally defined to be in the interval [0, π], except for π/2, which is not in the range of the arcsecant.
- Relation to Arccosine: The arcsecant can be expressed in terms of the arccosine: for || ≥ 1.
Variants and Related Words
- arcsec (abbr.): The standard abbreviation for arcsecant.
- The angle is arcsec(4).
- Inverse Secant: A synonymous phrase for arcsecant.
- Secant Inverse: An alternative, less common phrasing.
Synonyms
- Inverse secant function: The full descriptive name.
- sec⁻¹: The standard mathematical notation.
Notes
- The arcsecant is a transcendental function.
- It is one of the six principal inverse trigonometric functions, along with arcsine, arccosine, arctangent, arccosecant, and arccotangent.
- Handling the domain and range correctly is crucial, as the secant function is not one-to-one over its entire domain; its domain is restricted to [0, π] (excluding π/2) to define the inverse.
Noun
- the inverse function of the secant; the angle that has a secant equal to a given number