Quadruple jump controversy Quadruple jump controversy At the 2010 Winter Olympics held in Vancouver, British Columbia, Canada, the final results of the men's figure skating competition sparked what has been dubbed a quadruple jump controversy. At the heart of it lies a quadruple jump, the toughest jump there is in figure skating, done in combination with a triple toe loop, which Evgeni Plushenko of Russia landed in both his short and long programs. Evan Lysacek of the United States, however, did not include quads in either of his programs. Plushenko, who led Lysacek by half a point after the short figure skating program,
Quadruple product Quadruple product In mathematics, the quadruple product is a product of four vectors in three-dimensional Euclidean space. The name "quadruple product" is used for two different products, the scalar-valued scalar quadruple product and the vector-valued vector quadruple product or vector product of four vectors . The scalar quadruple product is defined as the dot product of two cross products: where a, b, c, d are vectors in three-dimensional Euclidean space. It can be evaluated using the identity: or using the determinant: The vector quadruple product is defined as the cross product of two cross products: where a, b, c, d