Scrabble?! SECH

Definitions of SECH in various dictionaries:

In mathematics, hyperbolic functions are analogs of the ordinary trigonometric, or circular, functions. The basic hyperbolic functions are the hyperbolic sine "sinh" (), and the hyperbolic cosine "cosh" (), from which are derived the hyperbolic tangent "tanh" (), hyperbolic cosecant "csch" or "cosech" ( or ), hyperbolic secant "sech" (), and hyperbolic cotangent "coth" (), corresponding to the derived trigonometric functions. The inverse hyperbolic functions are the area hyperbolic sine "arsinh" (also denoted "sinh1", "asinh" or sometimes "arcsinh") and so on. Just as the points (cos t, sin t) form a circle with a unit radius, the points (cosh t, sinh t) form the right half of the equilateral hyperbola. The hyperbolic functions take a real argument called a hyperbolic angle. The size of a hyperbolic angle is twice the area of its hyperbolic sector. The hyperbolic functions may be defined in terms of the legs of a right triangle covering this sector. Hyperbolic functions occur in the