(i) Prove that the semi-vertical angle of the right circular cone of given volume and least curved area is cot-1 √2
OR
(ii) A running track of 440m is to be laid out enclosing a football field. The football field is in the shape of a rectangle with a semi-circle at each end. If the area of the rectangular portion is to be maximum, then find the length of its sides. Also calculate the area of the football field.
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