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# 2: Graphs of the Trigonometric Functions

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• 2.1: Graphs of the Cosine and Sine Functions
The most basic form of drawing the graph of a function is to plot points. One thing we can observe from the graphs of the sine and cosine  functions is that the graph seems to have a “wave” form and that this “wave” repeats as we move along the horizontal axis.
• 2.2: Graphs of Sinusoidal Functions
In this section, we will study the graphs of functions whose equations are f(t)=Asin(B(t−C))+D and f(t)=Acos(B(t−C))+D where A,B,C , and D are real numbers. These functions are called sinusoidal functions and their graphs are called sinusoidal waves. We will first focus on functions whose equations are y=sin(Bt) and y=cos(Bt) .
• 2.3: Applications and Modeling with Sinusoidal Functions
A mathematical model is a function that describes some phenomenon. For objects that exhibit periodic behavior, a sinusoidal function can be used as a model since these functions are periodic. However, the concept of frequency is used in some applications of periodic phenomena instead of the period.
• 2.4: Graphs of the Other Trigonometric Functions
• 2.5: Inverse Trignometric Functions
• 2.6: Solving Trigonmetric Equations
An identity is a special type of equation. Equations that are not identities are also called conditional equations because they are not valid for all allowable values of the variable. To solve an equation means to find all of the values for the variables that make the two expressions on either side of the equation equal to each other. We solved algebraic equations in algebra and now we will solve trigonometric equations.
• 2.E: Graphs of the Trigonometric Functions (Exercises)