SOLUTION: Find the length and width of a rectangle that has the given perimeter and a maximum area. Perimeter: 48 meters

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Question 426053: Find the length and width of a rectangle that has the given perimeter and a maximum area.
Perimeter: 48 meters

Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
Solution:Denote the length of rectangle x m, since the perimeter is 48m then the width of rectangle is (24-x)m. We know that the area of rectangle is:
A=x%2A%2824-x%29
A=-x%5E2%2B24x This function introduce a downward parabola.
We find the vertex of this parabola: x=%28-24%29%2F%28-2%29=12
Since the length is 12m the width will be: 24-12=12m
We conclude that this rectangle has the maximum area when its shape is square of side 12m.
We find the value of area for x=12m : A%2812%29=-%2812%29%5E2%2B24%2A12
+A%2812%29=144+m%5E2.