00:01
All right, so we're given this notation, r with a little subscript, negative 90 degrees of 3 comma 2.
00:07
So what we want to see, this is a rotation of negative 90 degrees of this point 3 -2.
00:16
Now, it doesn't give us an indication of otherwise, so we are going to assume this is a rotation about the origin.
00:25
So what does this look like visually and then we'll calculate it? well, we want to imagine i'm taking this, imagine there's a little tethered point, 3 comma 2 over 3 up 2.
00:35
I want to rotate this 90 degrees, so it's negative 90.
00:39
So positive 90 would be our counterclockwise, so negative 90 is going clockwise.
00:45
So i'm going to rotate this 90 degrees, so it's as if this tether forms this 90 degree angle.
00:52
So as i see this is going to be moving kind of down here.
00:56
Well, what's this new coordinate going to be? a few different ways you can think about this.
01:00
Maybe you have a formula you might have memorized.
01:02
Now i noticed to get this effect, obviously this is just a sketch, but it's not just 3 negative 2.
01:08
That would keep it just straight of and down...