Year 8
Number and Algebra
Indices
Index notation is comparatively modern. The Greek writer Diophantus used the symbol \(\Delta^\text{T}\) to denote what we would call \(x^2\) and used K for \(x^3\). In medieval algebra, Q and C were used instead. Even in the 16th century, people were still writing \(xxx\) for \(x^3\). The modern notation didn't appear in texts until late in the 18th century. It is an extremely useful and efficient notation.