I NEED HELP PLEASE, THANKS! :)

  θ = {0, π/2, π, 3π/2, 2π} . . . . choice B

Step-by-step explanation:

In this equation, r will be a maximum where cos(4θ) is a maximum. That is where ...

  4θ = 2kπ . . . . for some integer k

Dividing by 4 gives ...

  θ = k(π/2)

  θ = {0, π/2, π, 3π/2, 2π} . . . . matches choice B

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You will note that the graph also has extremes at odd multiples of π/4. These are the locations where cosine is a minimum and r is negative. It can be argued that r is not a maximum at those points.

1st part is 64,000,000

2nd part 500,000

step-by-step explanation:

soo this can be solve by using the formula:

f = p( 1 + i)^ n

where f is the future profit

p is the initial profit

i is the percent increase

n is the number of years

a . f = 30000 ( 1.05)^n

b. f = 30000 ( 1.05)^15

f = $62,368