Circular Function Comprehension Problem: For circular functions such as \(\cos
x,\) the independent variable, \(x,\) represents the length of an arc of a unit
circle. For other functions you have studied, such as the quadratic function
\(y=a x^{2}+b x+c,\) the independent variable, \(x,\) stands for a distance along
a horizontal number line, the \(x\) -axis.
a. Explain how the concept of wrapping the \(x\) -axis around the unit circle
links the two kinds of functions.
b. Explain how angle measures in radians link the circular functions to the
trigonometric functions.