Answer:
p=-2
Step-by-step explanation:
-11=p-9
Add 9 to each side
-11+9=p-9+9
-2 =p
I don't know what method is referred to in "section 4.3", but I'll suppose it's reduction of order and use that to find the exact solution. Take
, so that
and we're left with the ODE linear in
:
Now suppose
has a power series expansion
Then the ODE can be written as
All the coefficients of the series vanish, and setting
in the power series forms for
and
tell us that
and
, so we get the recurrence
We can solve explicitly for
quite easily:
and so on. Continuing in this way we end up with
so that the solution to the ODE is
We also require the solution to satisfy
, which we can do easily by adding and subtracting a constant as needed:
Time taken for Kristin to catch up with the truck will be found using the formula
time=(distance)/(speed)
distance=20 km
speed=90 km/h
thus
time=20/90=2/9 hours
Answer: 2/9 hours