CPM Homework Help : PC Problem 6-84

Below is a graph of a periodic function and the line $y = 5$ . One of the intersection points is $\left(11.31, 5\right)$ .

First quadrant periodic curve, x axis scaled from 0 to 3, with 3 visible turning points, at (5, comma 12), (15, comma 2.5), & (25, comma 12), & hoirzontal line at y =5, first intersection of horizontal with curve at labeled point A, 11.31, comma 5), and at second intersection labeled, B.

What is the period of the function?
Hint (a):
Use the symmetry of the graph to find the coordinate of the intersection labeled as point $B$ .
Hint (b):
Set up an equation involving $B$ .
$15 − 11.31 = B − 15$
What is the coordinate for the point labeled $C$ ?
Hint (c):
Set up an equation involving $C$ .
$11.31 − 5 = 5 − C$

Added to graph, blue dots at the high turning points of (5, comma 12), & (25, comma 12), segment connecting 2 dots, labeled period.

Added to graph, 2 horizontal rays, lower on x axis, from the origin to 15, upper on y = 5, from (0, comma 5) to point labeled A.

Added to graph, 2 horizontal rays, upper on y = 5, from (0, comma 5) to point A, lower just below y = 5, from x = 0 to x = 5.