standard_description: Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.
problem_activity: Sylvia bikes home along a straight road from her friend’s house, a distance of 8 miles. The graph shows her journey:
[IMG]
Describe what may have happened. Be sure to include details about her pace, points that indicate a change in action, and where she starts and stops.
Are all sections of the graph realistic? Explain your reasoning.


aligns: no