## anonymous one year ago Find the dimensions of the rectangle of maximum area that can be formed from a 40-in. piece of wire

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1. asib1214

20 X 2

2. anonymous

i already tried that it is incorrect

3. asib1214

5 X 8

4. asib1214

yep!!!!!

5. Astrophysics

|dw:1436312621888:dw| the perimeter is 40 inches$l+l+w+w = 40 \implies 2l+2w = 40$ now we can solve for either width or length, so solving for length gives us $l = \frac{ 40-2w }{ 2 }$using this information we can find the area of a rectangle since we know area of a rectangle is just $A = length \times width$$A = l \times w$ so plugging our length into the area formula we have $A = (20-w)w = 20w-w^2$ I simplified the length by dividing by 2 from the initial length formula I made. So now to find the maximum area, we need to take the derivative, I leave the rest to you.