Optimization, Calculus.

3) A rectangular corral is being built adjacent to a river to pen in Sugar Dragons. These require at least 25 feet of fencing in each directions. (They can't fly, so fencing will be sufficient, but you guys already knew that.) The corral must be 16,200 square feet. What dimensions would minimize the length of the fencing? 4) Find the area of the largest rectangle that can be inscribed in the upper half of the circle: x2 + y? =36. (Hint: define a point on the function and use it to setup your equations)