Euclidean

The surface of a balloon is not an Euclidean space, and therefore does not follow the rules of Euclidean geometry.

The Euclidean algorithm serves not only to determine the greatest common divisor between two whole numbers, but also to solve Diophantine equations.

The Euclidean algorithm serves not only to determine the greatest common divisor between two integers, but also to solve Diophantine equations.

If (#92;alpha#95;1,#92;dots,#92;alpha#95;n) is an orthonormal basis of a euclidean space V, then for all #92;alpha,#92;beta in V#92;alpha#61;#92;sum#95;#123;i#61;1#125;ⁿ(#92;alpha#92;vert#92;alpha#95;i)#92;alpha#95;i#92;quad#92;text#123;and#125;#92;quad(#92;alpha#92;vert#92;beta)#61;#92;sum#95;#123;i#61;1#125;ⁿ(#92;alpha#92;vert#92;alpha#95;i)(#92;beta#92;vert#92;alpha#95;i).We turn now to a somewhat more profound matter. Suppose that we partially order by inclusion the collection of all orthonormal sets of vectors in a euclidean space V. A maximal element of this set is called a maximal orthonormal set.