Use the graph to write an equation
y = acos[b(x – h)] + k to model the situation.

b options are pi/12, pi/6, and pi/3

answer:

step-by-step explanation:

given equation   y = acos[b(x – h)] + k to model the situation,

the graph crosses y=24 at x=0 and x=10.

so that represents half a cycle of the cosine function.

the amplitude is defined as the difference between peak and baseline of a function. peak is at y=80 and baseline is y=24

the amplitude is 80-24 = 56

the cosine function's range is -1 to 1

so a = amplitude = 56

because a half-cycle is 10-0 = 10 months, a full cycle is 2*10 = 20 months.

the period = 20

2pi/b = 20

b = pi/10

if the options for b are as listed, then pi/12 is the closest answer.

step-by-step explanation:

the true statements are:

r = set of real numbers

n = set of natural numbers, 1,2,

w = n u{0} = {0,1,}