00:01
We're only in the first quadrant, that's important.
00:03
Y equals three x cubed is, i'm just trying to make it so there's some depth to it, but it is pretty skinny.
00:10
We also have the x axis, and on the right we have x equals one and what we're trying to do is revolve it about the line y equals negative one.
00:22
And so what we are gonna have to draw in here end up being washers.
00:27
So let me just jot that down.
00:30
And what the washer method is, is gonna be the volume going from, well it's pi first, going from zero to one, because we're in quadrant one.
00:39
And the upper function is that three x cubed, and you have to subtract off that negative one so it becomes plus one, it's like you're adding one to the radius being squared, minus the lower function is y equals zero, because that's the x axis, minus negative one squared dx.
01:01
There we go...