MathDB
Show that (SQRT(2) + 1)^n = SQRT(m) + SQRT(m-1)

Source: IMO Longlist 1989, Problem 31

September 18, 2008
inductionnumber theory unsolvednumber theory

Problem Statement

Let n n be a positive integer. Show that \left(\sqrt{2} \plus{} 1 \right)^n \equal{} \sqrt{m} \plus{} \sqrt{m\minus{}1} for some positive integer m. m.