Question

Let e = (1, 0) and f = (1, 1) be two points in 

R2 . Find ix - yl, 12x - y I , where x = e + f, 

y = 2e + 2f

Answer 1

$x = e + f = (1, 0)+(1, 1)= (2, 1) \\ y = 2e + 2f = 2x = (4, 2) \\ |x-y| = |x-2x| = |x| = \sqrt{2^2+1^2} = \sqrt{5} \\ |2x-y| = |2x-2x| = |0| = 0$