If the exterior angle of a regular polygon is 72°, how many sides does it have? what is another name for this shape?

f(x) = 4*cos(pi*(6/8)*x) + 2

Step-by-step explanation:

A generic cosine function is written as:

f(x) = A*cos(w*x + p) + M

where:

A = amplitude

w = angular frequency

p = phase

M = midline.

We know that:

the midline is 2, then  M = 2

the amplitude is 4, then A  = 4

There is no information about the phase, so p = 0.

And we know that the period is 8/3.

The period is written as T, and the relation between the period and the angular frequency is:

T = 2*pi/w

Then we have:

8/3 = 2*pi/w

w = (2*pi)*(3/8) = pi*(6/8)

where pi = 3.14

Then we have:

w =  pi*(6/8)

A = 4

M = 2

p = 0

Then the cosine function is:

f(x) = 4*cos(pi*(6/8)*x) + 2.