Question

Consider the set D of all numbers in the interval (-infinity , 5). What is the complement of D ?

Answer 1

I think it's (5, +infinity) . I've never see it .

Answer 2

The first is the set:
\[\{x\in R\phantom{.}|\phantom{.}x\in (-\infty,5)\}\]
The complement would be the rest of the number line from \(5\) to \(+\infty\) which is notated as :
\[\{x\in R\phantom{.}|\phantom{.}x\in (5,\infty)\}\]

Answer 3

The choices are
A.(-∞,-5)
B.[5,+∞)
C.(-∞,5)
D.(5+∞)

Answer 4

OOOOOH Well we know that \(5\) and \(+\infty\) are part of the interval so we are given the options of:
\([5,+\infty)\) and \((5,+\infty)\) EXACTLY, how as the original set notated?

Answer 5

I typed B & D the way it was on my paper . :c

Answer 6

Haha no like the original set not the complement, the one from negative infinity to 5

Answer 7

Like did it have two brackets like this:
\((\phantom{...})\)?

Answer 8

Everything that's on here is what's on the paper , & Yeah it was (-∞,5)

Answer 9

Set D does not include5, so the complement must include 5:

D': \([5, \infty) \)
The answer is B.