rectangular pen is built with one side against a barn If 1900 m of fencing are used for the other three sides of the pen, what dimensions maximize the area of the pen? rectar ensions of each pen that minimize the amount of fence that must be used? 225 225 225 225 Let A be the area of the rectangular pen and let x be the length of the sides perpendicular to the barn. White the objective function in a form that does not include the length of the side arallel to the barn Type an expression.) The interval of interest of the objective funcionsâ¡ (Simplity your answer. Type your answer in interval notation Do not use commas in the individual endpoints) Toma mize the area ofthe pen, te s des per en (Type exact answers, using radicals as needed) cular to the ban should beâ¡mong and the side paralel to the bam should be mln. b. Let x be the length of the sides perpendicular to thhe barn and let L be the total length of fence needed Wite the objective function Type an expression) The interval of interest of the objective function is (Simplity your answer. Type your answer in interval notation Do not use commas in the individual endpoints ) To minimize the amount of fence that must be used, each of the sides perpendicular to the barn should be 'm long and each of the sides parallel to the barn should bemlong (Type exat answers, using radicals as needed)