@rohitpi:
Hello! I'm the author of those methods notes. You said that the given solution to 2x^2-4>0, which was -root(2)>x>root(2) was incorrect. If you split up the inequality, looking at the first half only, it reads: -root(2)>x, that is: x is an element of (-infinity, -root2]. The second component, x>root(2) is the interval: [root2, infinity). When you put the two intervals together, the inequality is equivalent to the interval (-infinity, -root2]U[root2, infinity).
If we have a look at your proposed alternative, -root2<x<root2, it reads:
x is greater than -root2 and x is less than root 2. That is the interval [-root2, root2]. In short, I think you're incorrect, but thanks for raising it anyway!
@luken93:
The UMAT is run by ACER. ACER is a consortium, whose head works at Monash. I believe that's where the tie comes from.