Chapter 20
Graphing Two More Trig Functions
IN THIS CHAPTER
Using sine and cosine to graph cosecant and secant
Describing and graphing inverse functions
The functions cosecant and secant have similarities to one another not only because they’re the reciprocals of sine and cosine, but also because their graphs look very much alike. As you see in this chapter, the easiest way to sketch the graphs of these two functions is to relate them to the graphs of their reciprocals. Doing so helps determine the asymptotes (where the curve approaches infinity or negative infinity), turning points, and general shape of the curves.
Seeing the Cosecant for What It Is
The cosecant function is the reciprocal of the sine function (meaning, the cosecant equals the number 1 divided by the sine). Even though the sine function has a domain that includes every possible number, that characteristic can’t be true of its reciprocal. Whenever the sine function is equal to 0, the cosecant function doesn’t exist. That fact helps determine the asymptotes you use to graph the cosecant function.
Identifying the asymptotes
The domain of the cosecant function is any number except multiples of 
, because those measures ...
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