SOLUTION: The size of a Quantity Qi at time t is given by Q(t)=1300e^2.1t, Where t is measured in seconds. a) Is the quantity Q increasing or decreasing with time? b)what the initial v

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: The size of a Quantity Qi at time t is given by Q(t)=1300e^2.1t, Where t is measured in seconds. a) Is the quantity Q increasing or decreasing with time? b)what the initial v      Log On


   



Question 1093092: The size of a Quantity Qi at time t is given by Q(t)=1300e^2.1t, Where t is measured in seconds.
a) Is the quantity Q increasing or decreasing with time?
b)what the initial value of Q?
c) What is the value of Q after 1.5 seconds?
d)In how many seconds (measured from t=0)will the quantity be equal to 2000?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
as t increases, e^2.1t is increasing, since it is positive.
initial value is when t=0. Then Q(t)=1300*e^0=1300.
after 1.5 seconds, Q(t)=1300e^3.15=30336.88.
2000=1300e^2.1t
1.538=e^2.1t
ln both sides
0.4307=2.1 t.
without rounding divide by 2.1
t=0.2051
graph%28300%2C300%2C-5%2C2.5%2C-10%2C50000%2C1300%2Ae%5E%282.1x%29%29