Pre-Calculus For Dummies, 2nd Edition

Chapter 7

Simplifying the Graphing and Transformation of Trig Functions

In This Chapter

Plotting and transforming the sine and cosine parent graphs

Picturing and changing tangent and cotangent

Charting and altering secant and cosecant

“Graph the trig function. . . .” This command sends shivers down the spines of many pre-calc students. But we’re here to say that you have nothing to fear, because graphing functions can be easy. Graphing functions is simply a matter of inserting the x value (the domain) in place of the function’s variable and solving the equation to get the y value (the range). You continue with that calculation until you have enough points to plot. When do you know you have enough? When your graph has a clear line, ray, curve, or what have you.

You’ve dealt with functions before in math, but up until now, the input of a function was typically x. In trig functions, however, the input of the function is typically θ, which is basically just another variable to use. This chapter shows you how to graph trig functions by using various values for θ. We start with the parent graphs — the foundation on which everything else for graphing is built. From there, you can stretch ...