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: Find two values where
$${\mathrm{cos}x=-1}$$
.
What is
$${\mathrm{arccos}(-1)}$$
?


aligns: no