standard_description: Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.
problem_activity: Task
Use the graph (for example, by marking specific points) to illustrate the statements in
(a)–(d).  If possible, label the coordinates of any points you draw.
[IMG]
$f(0) = 2$
$f(−3)=f(3)=f(9)=0$
$f(2) = g(2)$
$g(x)>f(x)$ for $x>2$


aligns: no