Example TRIG.LCOMP.4 :Suppose $f$ is a trigonometric function
of the form $f_s(x)=2\sin(Bx+C)$ with period $ \pi$, and
maximum value $f(1)=2$. Find $B$ and one (of the many) possible
value(s) for $C$. Visualize $f$ with a mapping diagram that illustrates
the function as the composition of the three core functions
$f_{*2}\circ \sin \circ f_{+C} \circ f_{\times B}$.
Solution: Since the period, $2\pi/B = \pi$, simple algebra provides the
solution that $B = 2$. Since a maximum value for the sine occurs when
$Bb+C = B(1)+C =\pi/2$ and $B=2$, we have $2+C = \pi/2$ and thus $C
=\pi/2 -2$. So $f_s(x) =2\sin( 2x -2+\pi/2)$ will satisfy the required
conditions.
Here is the desired mapping diagram:
Martin Flashman, Feb. 19, 2017.
Created with GeoGebra
Notice how the arrows on the mapping diagrams are paired with the points on the graph of the functions.
You can move the point for $x$ on the mapping diagram to see how the
function value for the functions change both on the diagram and on the
graph.
The arrow on the point on the mapping diagram target axis indicates
whether the value of the function is increasing (pointing up) or
decreasing (pointing down).