00:01
Suppose the position of a particle at time t is defined by the function s of t, which is equal to one over t squared.
00:08
And here we want to find the velocity at time t, which is equal to a 1, 2 and three to do this, we find the derivative of s at a point t, which is equal to a.
00:23
Now by definition of the derivative at the point we have s prime of a.
00:28
This is equal to limit as t approaches a.
00:34
Of s f t minus s.
00:36
Of a fish all over t minus a.
00:41
So from here we have limits.
00:43
S t approaches a.
00:44
Of s f t, which is one over t squared.
00:47
This minus s of a.
00:49
Which is one over a squared all over t minus a.
00:57
Now combining the numerator, we have limit s.
01:01
T approaches a.
01:03
Of we have a common denominator of a square t squared and then we have a squared minus d squared.
01:11
This times the reciprocal of t minus a, which is one over t minus a.
01:17
And then from here we get limit.
01:19
Sd approaches a.
01:21
We can factor out a squared minus d squared into a minus t, times a plus t.
01:29
This all over a square times t squared and then times the reciprocal of t minus a, which is one over t minus e...