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Math Help - Limit as X aproaches - infinity

  1. #1
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    Limit as X aproaches - infinity

    I had this problem on a test, and it was only an alteration of a problem i had on a homework. But for some reason, if i use the same method to figure it, i get the wrong answer. I know the answer is 2/3 but i don't know the steps to solve it.

    Limit 2+10^x
    x→-∞ 3-10^x

    = 2/3

    My problem is how, >.< i can't figure it out. If it was positive infinity i would multiply by 1 or 10^-x/10^-x and get -1, but that doesn't seem to work. What am i missing?
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  2. #2
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    Quote Originally Posted by mortalapeman View Post
    I had this problem on a test, and it was only an alteration of a problem i had on a homework. But for some reason, if i use the same method to figure it, i get the wrong answer. I know the answer is 2/3 but i don't know the steps to solve it.

    Limit 2+10^x
    x→-∞ 3-10^x

    = 2/3

    My problem is how, >.< i can't figure it out. If it was positive infinity i would multiply by 1 or 10^-x/10^-x and get -1, but that doesn't seem to work. What am i missing?
    \lim_{x \rightarrow -\infty} 10^x = 0 \, ......
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  3. #3
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    Quote Originally Posted by mr fantastic View Post
    \lim_{x \rightarrow -\infty} 10^x = 0 \, ......
    well i hadn't thought about it that way....and that kinda just makes sense now >.<

    My teacher kinda sucks hard and only repeats the examples in the book. So thank you for showing me.
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