00:01
For a, the problem is showed that the curvature at each point of a street line is equal to 0.
00:12
B is show that the curvature at each point of a circle of a rider's r is 1 over r.
00:23
So here we have two formulas about the curvature.
00:29
For this one, x dot means x d t.
00:39
X2.
00:41
That means dx square d t squared.
00:51
For a, we can use this one.
00:56
For a, for a street line, y is equal to kx plus b.
01:06
I can write a x plus b.
01:09
We know, d y, d x square, second derivative is equal to zero.
01:21
So the curvature is zero...