This is an HTML5 applet to explore the properties of the graphs of cosine functions. The parameters \( a \), \( b \), \( c \), and \( d \) included in the definition of a cosine function of the form:
\[ f(x) = a \cos(bx + c) + d \]
may be changed to explore the graph of function \( f \). A radio button may be used to graph \( \cos(x) \) in order to compare and better understand the properties of \( a \cos(bx + c) + d \).