Attached is a drawing to set up the problem, hopefully that helps.
The red lines are tracing the rowing and walking to get to other side.
dR = distance rowed
dw = distance walked
x = the angle in which to start rowing initially
dR can be found by using Law of cosines
dw is arc length, which is just radius*arc
next we need t set up a function for Time in terms of x.
This is so we can minimize the time it takes to get to other side.
Time = distance/rate
Finally, take derivative and set equal to 0
Once you solve for x, plug it back into Time function to obtain final answer.
The red lines are tracing the rowing and walking to get to other side.
dR = distance rowed
dw = distance walked
x = the angle in which to start rowing initially
dR can be found by using Law of cosines
dw is arc length, which is just radius*arc
next we need t set up a function for Time in terms of x.
This is so we can minimize the time it takes to get to other side.
Time = distance/rate
Finally, take derivative and set equal to 0
Once you solve for x, plug it back into Time function to obtain final answer.