Quadruple jump controversy the early days of the Olympic Winter Games, skaters performed single jumps. By the middle of the 20th century, they had graduated to double jumps. By the 1980s, the triple Lutz was the benchmark for men. Throughout the '80s, it was the triple Axel, though attempts at a quad were already being made. Finally, a quadruple jump became an essential element in the programs of many men in the '90s and into the new millennium. The fact that fewer skaters than ever before attempt to land the toughest element in figure skating, opting to go for points instead, does not
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