The rate of change in revenue for Under Armour from 2004 through 2009 can be modeled by dR /dt = 13.897t + 284.653 t where R is the revenue (in millions of dollars) and t is the time (in years), with t = 4 corresponding to 2004. In 2008, the revenue for Under Armour was $725.2 million. †
(a) Find a model for the revenue of Under Armour. (Round your constant term to two decimal places.) R(t) = 6.9485t2+284.653 ln(t)-311.42 Correct: Your answer is correct.
(b) Find Under Armour's revenue in 2009. (Round your answer to two decimal places.) $ million

The  revenue is

Step-by-step explanation:

From the question we are told that

  The  rate of change  in revenue for Under Armour from 2004 through 2009 is  

Now  

Integrating both sides to obtain R(t)

=>  

From the question we have that at  t  = 8  

=>  

So  

At  t = 9  

Step-by-step explanation:

Data:

d = 8 m

l = 13 m

1. Lateral surface area

The lateral surface area is the side area, excluding that of the base.

The general formula for the lateral surface area L of a cone is

L = πrl

where r represents the radius of the base and l the slant height.

The base is a circle, so

r = d/2 = 8/2 = 4 m

L =π × 4 × 13 =

2. Total surface area

Total surface area = lateral surface area + area of base

S = L + B

The base is a circle, so

B = πr² = π(4)² = π × 16 = 50.36 m²

S = 163.4 + 50.36 =