History of Hindu Mathematics: A Source Book v2.c17.s24.31

v2.c17.s24.31

where λ is an arbitrary number. Putting λ = x, we get $u = ½(x² + x), y = ½(x² - x).$ Substituting this value of y in (2), we get $x² + x = 2v²,$ or $(2x + 1)² = 8v² + 1.$