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**harpazo** The cross-sectional area of a beam cut from a log with radius 1 foot is given by the function A(x) = (4x)(sqrt{1 - x^2}), where x represents the length, in feet, of half the base of the beam. Determine the cross-sectional area of the beam if the length of half the base of the beam is one-third of a foot.

Let me see.

There are 12 inches in one foot.

So, (1/3)(12) = 4 inches.

If x represents the length, in feet, of half the base of the beam, then I cannot let x = 4 inches. So, do I replace x with 1/3 in the given function and then simplify?