Tuesday, February 12, 2008

Scribe #7 (I think)

Hello back again for another scribe post. Sorry in advance to everyone who was waiting for the Friday's post, i was not able to get it up because of my internet connection to the blog was timing out. Well lets get into some math. Friday's class was all about rotating functions around the X-axis. Although this functions were not lines, they were functions like the area between two parabolas, or a function that had never been seen before. It started with a simple solids of revolution function, Find the volume of a solid revolution obtained by rotating the function x^2, bounded by the lines x=2 and x=1 around the x-axis. So here is a picture of that function revolved around the x-axis.
http://fooplot.com/index.php?q0=x%5e2

So between 1 and 2 we want to find the volume of the solid of revolution. So we find that once we make a cut and pull out a piece from the solid of revolution it looks like a circle with a hole in the middle. Where x^2 is the radius of the circle So the area of the circle is A(x)=Πr^2= Π(X^2)^2 =
Π(x^4).

So the volume of the solid of revolution is V=1,2
Π(x^4) dx = Π [x^5/5] 1,2 = [32Π/5] - [1Π/5] = 31Π/5.

After this question we took up questions in our homework from the previous night that we were not able to complete. The next scribe is going to be Dino once again.


No comments: