A rectangular animal pen is to be built against a straight section of river
MATHEMATICS · Subjective · CBSE · Mathematics · Applications of Derivatives · Applications of Derivatives
Problem
A rectangular animal pen is to be built against a straight section of river, so only three sides require fencing. The side parallel to the river costs $18 per foot, while each of the two sides perpendicular to the river costs $10 per foot. If the farmer can spend at most $4800 on fencing, let x be the length, in feet, of the side parallel to the river. Determine the dimensions of the pen that maximize the enclosed area, and state that maximum area.