WITCH OF AGNESI Witch of Agnesi/-an-'ya-ze/ [Maria Gaetana Agnesi 1799 It. mathematician; probably from its resemblance to the outline of a witch's hat]: a plane cubic curve that is symmetric about the y-axis, approaches the x-axis as an asymptote, and has the equation x2y=4a2(2a-y).       Your flight begins low       casual       then rising       swelling like a wave       you arc the moon       reach a peak       &       sensing the symmetry       descend       drawn toward the pattern       of a curve       beautiful in its simplicity       you ride it out       the line perfect       the equation complete