$\"\"$ \ \

A wooden beam has a rectungular cross section of height $\"\"$ and width $\"\"$ . \ \

$\"\"$ . \ \

Let $\"\"$ be the strength and $\"\"$ is the constant proponality. \ \

$\"\"$ \ \

$\"\"$

$\"\"$ \ \

First derivative is $\"\"$ for $\"\"$ . \ \

$\"\"$ when $\"\"$ inches and $\"\"$ inches. \ \

$\"\"$ which yeilds a maximum value. \ \

$\"\"$ \ \

Width, $\"\"$ inches and Height, $\"\"$ inches.

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