## anonymous one year ago choose the graph of y = 4/3 cos 3/2x

1. anonymous

2. DanJS

First, what are the maximum and minimum values for cos(x)

3. anonymous

4/3 -4/3

4. DanJS

$-1 \le \cos(x) \le 1$

5. DanJS

the amplitude in this case, is A*cos(x) , 4/3

6. DanJS

The graph isnt shifted vertically, so the max and min are 4/3, -4/3 now just have to figure out the period.

7. anonymous

cosine has a period of 2pi/b

8. anonymous

so would it be 2pi/ (3/2) ?

9. DanJS

yes

10. DanJS

so 4/3 pi for the period...

11. DanJS

Graph: y = A*cos( B*x + C) + D make sliders for A, B, C, D, and play arouind with changing those values, and watch the graph

12. DanJS