• etchinghillside@reddthat.com
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    7 hours ago

    It’s been a while… but isn’t that negative?

    Or is there some default given of which side it’s approaching from.

    • Ooops@feddit.org
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      2 hours ago

      It should be +/-∞

      Minus or plus depending on the side from which you approach the limes.

    • Sculptus Poe@lemmy.world
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      6 hours ago

      (Just including the graph for reference. I’m not sure it helps with proper description or the answer the teacher was asking for, but you can see that from one direction it goes negative as you approach 8 and from the other it goes to positive infinity.)

    • LeFrog@discuss.tchncs.de
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      7 hours ago

      I think it is not defined. It has a limes from the left (- inf) and limes from the right (+ inf) but no two-sided limes.

      Edit: wolframalpha agrees but I don’t know for sure

    • JustAPenguin@lemmy.world
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      6 hours ago

      I have a BA in Mathematics. The limit is indeed determined by the direction you approach the limiting value.

      When given without specification, the limit is implied to come from the left, meaning it increases towards the limiting value, which is why you see +inf.

      • rooroo@feddit.org
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        6 hours ago

        Yeah but then it should be negative infinite, cause if x<8 the fraction is negative.

        • JustAPenguin@lemmy.world
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          6 hours ago

          Ah, I misread the - as a +. You’re correct! Sorry, I just woke up and am in the middle of my morning doomscrolling sesh

          • deadbeef79000@lemmy.nz
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            5 hours ago

            Conveniently modeled with the same limit.

            Though I’m not sure what negative doom is and what happens when it approaches infinity.