Answer
Quaternions, a significant mathematical discovery made by Hamilton in 1843, extended the concept of complex numbers to four dimensions. These entities, represented as a+bi+cj+dk, where a, b, c, and d are real numbers and i, j, and k are imaginary units, allowed for the representation and manipulation of rotations in three-dimensional space. Quaternions found applications in various fields, including physics, engineering, and computer graphics.