Fen

A fen is one of the main types of wetland, the others being grassy marshes, forested swamps, and peaty bogs. Along with bogs, fens are a kind of mire. Fens are usually fed by mineral-rich surface water or groundwater. They are characterised by their water chemistry, which is pH neutral or alkaline, with relatively high dissolved mineral levels but few other plant nutrients. They are usually dominated by grasses and sedges, and typically have brown mosses in general including Scorpidium or Drepanocladus. Fens frequently have a high diversity of other plant species including carnivorous plants such as Pinguicula. They may also occur along large lakes and rivers where seasonal changes in water level maintain wet soils with few woody plants. The distribution of individual species of fen plants is often closely connected to water regimes and nutrient concentrations.

Fens have a characteristic set of plant species, which sometimes provide the best indicators of environmental conditions. For example, fen indicator species in New York State include Carex flava, Cladium mariscoides, Potentilla fruticosa, Pogonia ophioglossoides and Parnassia glauca.

Car (surname)

Car is a surname. Notable people with the surname include:

Car (Greek mythology)

Car or Kar (Greek: Κάρ) is a name in Greek mythology that refers to two characters who may or may not be one and the same.

The name "Car" is unrelated to the English word "car" (vehicle).

Car of Megara

According to Pausanias, Car was the king of Megara and the son of Phoroneus (and Cerdo). His tomb was located on the road from Megara to Corinth. The acropolis at Megara derived its name Caria from him.

Car of the Carians

Herodotus mentions a (probably) different Car, brother of Lydus and Mysus; the three brothers were believed to have been the ancestral heroes and eponyms of the Carians, the Lydians and the Mysians respectively. This Car was credited by Pliny the Elder with inventing the auspicia.

Car was also said to have founded the city Alabanda, which he named after Alabandus, his son by Callirhoe (the daughter of the river god Maeander). In turn, Alabandus's name is said to have been chosen in commemoration of his Car's victory in a horse fight— according to the scholar Stephanus of Byzantium, "Alabandos" was the Carian word for "winner in a horse fight". Another son of Car, Idrieus, had the city Idrias named after himself.

Inverse trigonometric functions

In mathematics, the inverse trigonometric functions (occasionally called cyclometric functions) are the inverse functions of the trigonometric functions (with suitably restricted domains). Specifically, they are the inverses of the sine, cosine, tangent, cotangent, secant, and cosecant functions. They are used to obtain an angle from any of the angle's trigonometric ratios. Inverse trigonometric functions are widely used in engineering, navigation, physics, and geometry.

Notation

There are several notations used for the inverse trigonometric functions.

The most common convention is to name inverse trigonometric functions using an arc- prefix, e.g., arcsin(x), arccos(x), arctan(x), etc. This convention is used throughout the article. When measuring in radians, an angle of θ radians will correspond to an arc whose length is rθ, where r is the radius of the circle. Thus, in the unit circle, "the arc whose cosine is x" is the same as "the angle whose cosine is x", because the length of the arc of the circle in radii is the same as the measurement of the angle in radians. Similar, in computer programming languages (also Excel) the inverse trigonometric functions are usually called asin, acos, atan.

Arc (Everything Everything album)

Arc is the second studio album by British indie pop band Everything Everything. It was released in the United Kingdom on 14 January 2013, having been preceded by the singles "Cough Cough" and "Kemosabe".

Track listing

Critical reception

Freddie Holmes of The Underclassed gave the album a positive review stating:

7digital featured Arc as album of the week, praising the record as "schizophrenic, electro-pop perfection."

Personnel

References

Arc (projective geometry)

A (simple) arc in finite projective geometry is a set of points which satisfies, in an intuitive way, a feature of curved figures in continuous geometries. Loosely speaking, they are sets of points that are far from "line-like" in a plane or far from "plane-like" in a three-dimensional space. In this finite setting it is typical to include the number of points in the set in the name, so these simple arcs are called k-arcs. An important generalization of the k-arc concept, also referred to as arcs in the literature, are the (k, d)-arcs.

k-arcs in a projective plane

In a finite projective plane π (not necessarily Desarguesian) a set A of k (k ≥ 3) points such that no three points of A are collinear (on a line) is called a k - arc. If the plane π has order q then k ≤ q + 2, however the maximum value of k can only be achieved if q is even. In a plane of order q, a (q + 1)-arc is called an oval and, if q is even, a (q + 2)-arc is called a hyperoval.

Every conic in the Desarguesian projective plane PG(2,q), i.e., the set of zeros of an irreducible homogeneous quadratic equation, is an oval. A celebrated result of Beniamino Segre states that when q is odd, every (q + 1)-arc in PG(2,q) is a conic. This is one of the pioneering results in finite geometry.