A structural engineer calculates that the side length, sss decimetres, of a square support column must satisfy the equation s2=13s^2 = 13s2=13 to meet safety specifications.
Use proof by contradiction to prove that sss is an irrational number.
(You may assume that for any integer nnn, if n2n^2n2 is a multiple of 13, then nnn is a multiple of 13).
368 exam-style questions on Edexcel A Level Maths Algebraic Methods, covering 1.1 Proof by Contradiction, 1.2 Algebraic Fractions, 1.3 Partial Fractions, 1.4 Repeated Factors, and 1.5 Algebraic Division. Each one has a worked solution and a mark scheme showing where the marks go.