Related Rates Video on TI-89: Square Area Increasing  

Raw Transcript

Hello everyone Tom from every step calculus dot com.
Related rates problem.
Right off of Yahoo on the Internet.
Where they ask the questions and
a lot of them try to answer it. Let’s get started, index8() to go to my menu.
And
going to, all the instructions come with my programs of course how to do all this
stuff. We’re going to,
go down to related rates.
Scroll down related rates because that’s the problem
we’re doing.
Here we are here, and we
these are all alphabetical everything is you wanna get to
this problem involving a square the area of a
square. So we’re gonna go down, that choice on the menu.
And
related rates always deals with a formula and then
changes that to derivatives with respect to time.
And so you write all this down area equals s squared.
I give you this little hint, s equals a side and we’re gonna find
da/dt the how the area is changing
with regard to time. And so
now we’re gonna do the calculation here’s the a equals s squared where there’s a
formula and we do the derivative
left side derivative of the right side with respect to T
time. And that turns into
the derivative of area with respect to time and then we have
derivative of s squared which is 2s.
And then ds/dt. This problem they give you area so we’re gonna choose that.
Otherwise they might give you side.
You try to make all those choices for you.
You have to press alpha before you enter anything in these entry lines. I’m gonna press alpha
give you 64
as the area.
I always show you in case you made a mistake I say it’s okay.
and of course the square root of the area is the side.
The formula is inside so we have to change it to that, so that’s 8
And then they give you centimeters.
They might give you any these. And the side is increasing at alpha,
8 centimeters per second
Again I show you its
8 centimeters for the side and 8 centimeters per second for the
change in the side which is ds/dt with regard to time.
Ok, so here’s the
answer you do the problem,you insert variables
Here’s the formula what we found before you insert the variables and you come up with this
answer.
Pretty neat huh? every step calculus dot com You can go to my site buy my program
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