00:04
Okay, here's my circular track.
00:07
The blue dot is where derek starts.
00:15
And we can find the angle, because we know that arc length is r times theta, radius times angle.
00:33
So the angle is that length divided by r.
00:41
And the length they gave us that he runs is 2 .7 kilometers.
00:49
And the radius is 0 .6 kilometers.
00:53
So our angle in radians, 2 .7 divided by 0 .6 is 4 .5 radians.
01:06
So what does that look like? well, right here, let me just draw like the initials.
01:17
So this is the initial side of our angle.
01:20
Right here is 3 pi over 2 radians.
01:26
So if we work that out on the calculator, 3 halves times pi, it's 4 .7 radians as a decimal.
01:37
So he's pretty close to 3 pi over 2, but not quite there.
01:40
So let's say, well, you know what? how much is pi radians as a decimal? well, that's 3 .14.
01:57
And he's at 4 .5.
01:58
So he's definitely closer to down here.
02:04
So let's say he's about there, just so we can visualize it.
02:10
And we got our answer for the first part.
02:13
It's 4 .5 radians.
02:17
So then parts b and c says when he stopped skiing, how many kilometers is derek to the right of the center of the ski trail? how many kilometers is derek above? that's weird, because he's not to the right and he's not above, he's to the left and he's down.
02:42
So maybe we just need to put negative numbers in there, but that's poorly worded.
02:55
But in other words, they're asking us to figure out his coordinates.
03:01
If this is our origin, really they want to know what are the coordinates that he's at now...