Trigonometric cosecant

Three further trigonometric functions,cosecant, secant and cotangent, are provided by the reciprocals of the basic functions ... 

The ordinary trigonometric functions include the sine, the cosine, the tangent, the cotangent, the secant, and the cosecant. These are sometimes called the circular trigonometric Junctions to distinguish them from the hyperbolic trigonometric functions discussed briefly in the next section of this chapter. 

The other hyperbolic trigonometric functions are the hyperbolic tangent, denoted by tanh(x) the hyperbolic cotangent, denoted by coth(x) the hyperbolic secant, denoted by sech(x) and the hyperbolic cosecant, denoted by csch(x). These functions are given by the equations... 

The trigonometric functions illustrate a general property of the functions that we deal with. They are single-valued for each value of the angle a, there is one and only one value of the sine, one and only one value of the cosine, and so on. The sine and cosine functions are continuous everywhere. The tangent, cotangent, secant, and cosecant functions are piecewise continuous (discontinuous only at isolated points, where they diverge). 

There are many practical applications in engineering for the trigonometric functions sine, cosine, tangent, secant, cosecant, and cotangent. These functions are defined as the ratios of the sides of plane right triangles. These functions are shown in Table 7.12. 

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