1. ## optimization problem

a lighthouse is 6km off shore and acabin on the straight shoreline is 9km from the point of the shore nearest to the lighthouse. If a man rows at a raw of 3km/hr, and walks at a rate of 5km/hr, where should he beach his boat in order to get from the lighthouse to the cabin as quickly as possible?

not really sure where to start. some hints would be great!

2. Originally Posted by iluvcalculus
a lighthouse is 6km off shore and acabin on the straight shoreline is 9km from the point of the shore nearest to the lighthouse. If a man rows at a raw of 3km/hr, and walks at a rate of 5km/hr, where should he beach his boat in order to get from the lighthouse to the cabin as quickly as possible?

not really sure where to start. some hints would be great!
Take the shore line as the x-axis, with origin at the point closest to the
light house.

Now assume the man rows to x on the shore and walks from there.

Now calculate the time he takes, and then find the minimum as x is allowed to
vary.

RonL

3. Originally Posted by CaptainBlack
Take the shore line as the x-axis, with origin at the point closest to the
light house.

Now assume the man rows to x on the shore and walks from there.

Now calculate the time he takes, and then find the minimum as x is allowed to
vary.

RonL
hey thanks a lot, but i already go the answer =D. it was just the wording of the question that really confused me.