Question
A farmer is building a rectangular enclosure against a long straight wall. He has 100m of fencing and only needs to fence three sides. Let the width perpendicular to the wall be x.
[7 marks]
(a)Show that the area A is given by A = 100x - 2x².
(b)Find dA/dx.
(c)Find the value of x that gives the maximum area.
(d)Calculate the maximum area.
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