CPM Homework Help : PC Problem 9-27

The graph at right is the result of a transformation of $y = \cos x$ . Find a possible equation.

Hint 1:

Focus on the two given points. What can it tell you?

Hint 2:

1. The amplitude is $3$ .
2. The period and frequency is normal.
3. The vertical shift is $5$ .
4. The horizontal shift is $\frac{\pi}{2}$ .

(Be careful when you write this in your equation.)

Answer:

$y = 3\text{cos}\left(x - \frac{\pi}{2}\right) + 5$

Periodic curve, x axis scaled from negative 1 fourth pi to 2 pi, with 2 visible turning points. first at (1 half pi, comma 8), second at (3 halves pi, comma 2), passing through highlighted points (0, comma 5), & (pi, comma 5).