A farmer has of fencing to construct a rectangular pen with one side bordering a…

MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

A farmer has 300 m300\text{ m} of fencing to construct a rectangular pen with one side bordering a straight river, so no fencing is needed along the river. The two sides perpendicular to the river each have length xx, and the side parallel to the river has length yy. To maximize the enclosed area, what should be the length of the side parallel to the river? (a) 100 m100\text{ m} (b) 75 m75\text{ m} (c) 150 m150\text{ m} (d) 225 m225\text{ m}

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