real numbers, question 4, grade 9

20/06/2016 Grade 9 2,888

4)

Given:  x=\sqrt5+1\,\,and\,y =\sqrt5-1

a) Calculate  {x^2}\&{y^2}\,

b) Prove by using the previous results that  \frac{x}{y}+\frac{y}{x} is a natural number.