standard_description: Prove the Pythagorean identity sin^(2)(θ) + cos^(2)(θ) = 1 and use it to find sin(θ), cos(θ),or tan(θ) given sin(θ), cos(θ), or tan(θ) and the quadrant of the angle.
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