Example TRIG.DID.0 Dynamic Visualization of Increasing and Decreasing for Trigonometric Functions: Graphs, and Mapping Diagrams
Notice how the arrows on the mapping diagrams are paired with the points on the graph of the functions.
You can use the sliders to adjust the values of $B$ and $C$ or enter them in the appropriate boxes.
You can move the point for $x$ on the mapping diagram to see how the function value for the function $ f(x) = trig( Bx+C)$ changes 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 $f(x)$ is increasing (pointing up) or decreasing (pointing down).
Notice how the graph and mapping diagram visualize the connection between the function and the basic shape of $trig(x)$.

See Subsection TRIG.LCOMP


Check the box to show points on the graph and arrows on the diagram for the function $ f(x)$.
Move the slider to change the function between $\cos$, $\sin$ and $\tan$.