# Calculus optimization problem

posted by
**Sam**
.

A rectangular dog run is to contain 864 ft ^2.

a. If the dog's owner must pay for fencing, what should be the dimensions of the run to minimize cost?

b. Suppose a neighbor has agreed to let the owner use an already constructed fence for one side of the run. What should the dimensions of the run be in this situation if the owner's cost is to be a minimum?

Can you explain how to do this?