witchof Agnesi

witch of Ag·ne·si (än-yāʹzē) n.

A planar cubic curve that is symmetric about the y-axis and that approaches the x-axis as an asymptote. Its equation is x²y = 4a²(2a - y), where a is a constant.

  [witch(translation of Italian avversiera, versiera, confused with versiera, curve, turning, from New Latin versōria, from Latin versus, turned, reversed, past participle of vertere, to turn. See verse¹) + Maria Gaetana Agnesi (1718-1799), Italian mathematician.]

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