standard_description: Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values.
problem_activity: Task
Pictured below are the graphs of four different functions, defined in terms of eight constants:  $a, b, c, k, m, p, q, \text{ and } r.$  The equations of the functions are:
$y=mx+b$
$y=a\cos(x)+c$
$y=qr^x$
$y=kx^p$
[IMG]
Match each equation with its graph.
Use the graphs to answer the following questions.  Justify your answers with appropriate explanations.
Which of the 8 constants are definitely negative?
Which of the 8 constants are definitely positive?
Which of the 8 constants are  definitely greater than zero but less than one?
Which of the 8 constants are definitely greater than one?


aligns: no