\sqrt{N^2 + d} \, \approx \, N + \frac{d}{2\,N} [/psypsych?title=Square_root&action=edit§ion=8 title=Square root>edit] Bakhshali approximation The Bakhshali square root approximation is a mathematical method for finding an approximation to a square root which was described in an ancient manuscript by the name of The Bakhshali Manuscript because it was discovered in 1881 near the village