00:01
This question this diagram will be formed so here in this diagram this point represents the board and this hypotenuse is representing the rowing distance and this point is a landing point this point is a landing point and this is represented by village which is represented by capital v and this distance is x minus s as this is x and the total distance is 6.
00:37
Now, from this point to this point, so this distance is walking distance.
00:45
This distance is walking distance and it is given that this is equals to 2 kilometer.
00:53
Now, here l is the landing point which is 6 -x km away from village.
01:13
6 -x km away from village.
01:19
Now, rowing distance will be given y.
01:22
So, from here using pythagoras theorem rowing distance will be equals to under root square of 2 square of perpendicular plus square of base.
01:36
So, now time required to cross the river.
01:49
To cross the river so that will be equals to rowing distance x square plus 4 upon rowing speed and time required for walking so that will be be equals to walking distance upon speed.
02:14
Now, total time will be time required for rowing the river and plus time required for walking.
02:29
Now, derivative of t with respect to x...