The man is in boat
from the nearest point on the coast.
He is to go to a point
, located
down the coast and
inland.
The man can row at speed of
and walk at
.
Observe the diagram,
\
and
.
.
Here the time is considered for both the man can row in water and walking time.
\The time taken by man to reach the point
is
.
.
Apply derivative on each side with respect to
.



The man can reach the point
in minimum time when
.










.
Let
.
Apply derivative on each side with respect to
.

.
Since
and
, the solution is in the interval
.
Newton
s approximation method formula :
.
Substitute
and
.
.
Perform Newton approximation for
.
The calculations for si iterations are shown in the table.
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Observe the table:
\The minimum time approximation is
.
The minimum time approximation is
.