Posted by Jake on Wednesday, January 18, 2012 at 8:40pm.
1. The height of a bumble bee above the ground is modelled by h(t) = 0.5cos(2π t) + 2, where h is in metres and t
is in seconds. At what time is the bee’s instantaneous rate of change of height with respect to time greatest?
a.) 1 s
b.) 1.25s
c.) 1.5s
d.) 2s
Why is the answer b?

2. What value for the function y=3cos(tpi) + 2 gives an instantaneous rate of change of 0?
a) 0
b) pi/2
c) pi/3
d) pi/4
I tried to plug in the options above, but it gave me 4.99999. How do I do this question?

3. The height of a ball is modelled by the equation h(t)= 4sin(8πt) + 6.5 where h(t) is in metres and t is in seconds. What are the highest and lowest points the ball reaches?
a) 10.5 m and 6.5m
b) 10.5 and 2.5m
c) 6.5m and 2.5m
d) 14.5 and 6.5m
I know that answer won't be B because it has to start at 6.5m

Math  Damon, Wednesday, January 18, 2012 at 8:56pm
1. The height of a bumble bee above the ground is modelled by h(t) = 0.5cos(2π t) + 2, where h is in metres and t
is in seconds. At what time is the bee’s instantaneous rate of change of height with respect to time greatest?
a.) 1 s
b.) 1.25s
c.) 1.5s
d.) 2s
Why is the answer b?
when is
d/dt 0.5cos(2π t)
biggest?
d/dt =  pi sin(2 pi t)
we want sin(2 pi t) = 1 or 1
that is when 2 pi t = pi/2, 3pi/2, 5 pi/2 , 7 pi/2 ...
t = 1/4 or 3/4 or 5/4 or 7/4 ....
the 5/4 is your 1.25

Math  Damon, Wednesday, January 18, 2012 at 9:04pm
2.
sin(tpi) = 0
t = 0, or pi, or 2 pi
perhaps they mean the value of t, not of the function. then t = 0 works

Math  Damon, Wednesday, January 18, 2012 at 9:05pm
3.
6.5+4 and 6.54
10.5 and 2.5

Math  Jake, Wednesday, January 18, 2012 at 9:11pm
I am still confused for number 2.
For number 3, you used the amplitude(which is 4) to find lowest+highest?
Answer This Question
Related Questions
 English  I had to write a story about a bee, tell me what you think. The bumble...
 Math  A batter hits a baseball straight up into the air. The height of the ball...
 Math Quadratic Equations . URGENT!!!!  A toy rocket is launched form a 3m ...
 Math, Quadratic equations  A toy rocket is launched form a 3m platform, at 8.2m...
 Math, Quadratic equaitons  A toy rocket is launched form a 3m platform, at 8.2m...
 Calculus  The height above the ground of a rider on a large Ferries wheel can ...
 instantaneous rate of change problem  Joe is investigating the rate of change ...
 Calculus  (Bees collecting pollen and nectar  Optimization) Many bees collect ...
 quadratics  a firework is modelled by the relation h=4.9(t9)^2+170 h=height ...
 Math  The height, h, in metres, above the ground of a rider on a Ferris wheel ...
More Related Questions