00:01
In this problem we are given that r dash of t equals to 2 times cos of t i vector plus 3 times sine of t j vector plus 2 times t k vector.
00:17
And we are also given that r of pi over 2 equals to 1 negative 2 pi squared over 4.
00:27
We are asked to find out the value of the vector r of t.
00:33
So in order to find out the vector r of t, we integrate the given first derivative of r of t.
00:40
So that is r of t equals to the integral of r dash of t with respect to t.
00:48
So let us integrate each of the components.
00:51
The integral of koss of t is sine of t.
00:54
So we get 2 times sine of t plus the constant of the.
00:58
Of integration c1, the whole multiplied with i vector, plus the integral of sine of t is negative cos of t.
01:06
So we have negative 3 times cause of t plus the constant of integration c2 times j vector plus the integral of t is t squared over 2.
01:20
Multiplying with 2 we get just t squared.
01:23
So we have t squared plus c3 that is the constant of integration times k vector.
01:30
So this is the answer for r of t.
01:32
Let us make use the condition that is given, that is r of pi over 2.
01:37
This equals to 1 negative 2 and pi squared over 4...