standard_description: Describe qualitatively the functional relationship between two quantities by analyzing a graph (e.g., where the function is increasing or decreasing, linear or nonlinear). Sketch a graph that exhibits the qualitative features of a function that has been described verbally.
problem_activity: Find two values where
$${\mathrm{cos}x=-1}$$
.
What is
$${\mathrm{arccos}(-1)}$$
?


aligns: no