>> [music] Welcome back to Calculus One
and welcome to Week 7 of our time
together.
We've been at this for a while already and
much of the time that we spent thus far
has just been on the mechanics of how to
calculate derivitaves.
Looking ahead, we've got three weeks now
to really focus in on why you'd want to
calculate derivatives, applications, or
differentiation.
This week, in Week 7, we've got two
applications lined up.
The first is L'Hopital's rule.
It's a way to evaluate limits by using
derivatives.
And it allows you to calculate limits that
would be very hard to calculate without
access to L'hopital's Rule.
The second application this week is
related rates.
There's a ton of situations in the real
world where you've got two things, and
they're changing together.
And you want to know if one thing is
changing at some speed, say, how fast is
the other thing changing?
There's rates of change and you want to
know how they're related.
Well, I hope you enjoy these applications.
We've got two more weeks after these
sub-applications.
If you've got questions, be sure to post
your questions on the forum, or come and
talk to us at office hours.
Good luck.