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Math Help - Show surjective HELP...

  1. #1
    Super Member
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    Show surjective HELP...

    Hello, can someone help me show that the following function is surjective (onto)?

    f: Z -> G, where Z = integers and G = {10^n : n e Z}

    So, we have f(n) = 10^n

    Take any y e G. Then y = 10^x for some x.

    => Taking ln of both sides gives x = ln(y)

    What do I do from here? Thanks
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  2. #2
    MHF Contributor
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    Re: Show surjective HELP...

    Hey jzellt.

    You can show that each value is unique in the co-domain (also you may want to change ln(y) to log_10(y)).
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