...I was wondering.. What is the difference between:

(2, infinity) and {x: x > 2}

these two say the same thing

And also:

R^+ union {0} and [2, infinity)

all non-negative real numbers ... x>2

Are these the same things written differently? And if so, if a question had the answer {x: x > 2} for example, and I wrote [2, infinity) instead, would I get it wrong? (Especially in exams)

[2, infinity) includes the value 2 ... x > 2 does not