SOLUTION: using 24 feet, what is the largest rectangle area possible?

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Question 517998: using 24 feet, what is the largest rectangle area possible?
Answer by solver91311(24713)   (Show Source): You can put this solution on YOUR website!


Presuming you mean a maximum 24 foot perimeter:

The rectangle with the greatest area for a given perimeter is a square with sides that measure the perimeter divided by 4.

The perimeter of a rectangle is given by:



The area of a rectangle is given by:



Substituting from the perimeter equation:



This function graphs to a parabola opening downward meaning that the vertex is a maximum.

Algebra solution: The vertex is the maximum, so for a parabola with equation , the vertex is at . For this parabola:

Calculus solution: The maximum value of the function, hence the maximum area, is where the value of the first derivative is equal to zero:



Set equal to zero:



Hence, the maximum area rectangle for a given perimeter is a square with sides of length one-fourth of the perimeter.



John

My calculator said it, I believe it, that settles it
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