Question

# 1) The altitude (in feet) of a rocket *t* sec into flight is given by

s=f(t)=

-t^{3}+60t^{2}+570t+6

Find the point of inflection of the function f.

(t,s)=?

What is the maximum velocity attained by the rocket?

2)The total annual revenue *R* of a certain resort hotel is related to the amount of money *x* the hotel spends on advertising its services by the function

R(x)= -0.002x^{3}+1.5x^{2}+5x+7000

where both R and x are measured in thousands of dollars

(a) Find the interval where the graph of R is concave upward (use interval notation.)

Find the interval where the graph of R is concave downward (use interval notation.)

(b) What is the inflection point at the graph of R?

(c) Would it be more beneficial for the hotel to increase its advertising budget slightly when the budget is $240,000 or when it is $260,000?

#### Top Answer

Q>1. So, inflection point is (t,s)= ( 20, 27406) So, maximum velocity is V(max)= V(20)= 1770 ft... View the full answer