I think it D cause 30(cos(30x)+14=-16
Your dividing by 30
your 180 (which is degrees) is
radians. As the cosine function is periodic with period 2 we get
Answer:15
Step-by-step explanation:
Given
Craftsman sell 10 Jewelry set for $500 each
For each additional set he will decrease the price by $ 25
Suppose he sells n set over 10 set
Earning
Earning 

differentiate to get the maximum value

Equate
to get maximum value



Thus must sell 5 extra set to maximize its earnings.
Your answer is C If not A have a good day