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名無しさん＠英語勉強中

Water is flowing into a conical vessel at the rate r. The vessel has the shape of a right circular cone, with horizontal base, the vertex pointing downwards; the radius of the base is a, the altitude of the cone b.
Find the rate at which the surface is rising when the depth of the water is y. Finally, obtain the numerical value of the unknown supposing that a=4 ft., b=3 ft., r=2 cu.ft.per minute, and y=1 ft.
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