Common Logs

Add yours

Sorry, we don't have any videos for this topic yet.
Let teachers know you need one by requesting it

Log in so we can tell you when a lesson is added.

Key Questions

  • There are 2 ways.

    The math way is to understand how to convert bases:

    #log a=(ln a)/(ln 10)#

    The second way is to use the "CATALOG" button, "L", scroll down to "log" and press enter.

    Here is an example of #log 50#:

    #=(ln 50)/ln(10)#
    #~~1.69897#

  • Answer:

    See the explanation.

    Explanation:

    If you have technology available for the logarithm in some other base (#e# or #2#), use

    #log_10 n = log_b n / log_b 10# (where #b = e " or "2#)

    With paper and pencil, I don't know a good series for #log_10 n#.

    Probably the simplest way is to use a series for #ln n# and either a series or memorization for #ln 10 ~~ 2.302585093#

    For #ln n#, let #x=n-1# and use:

    #ln n = ln (1 + x) = x − x^2/2 + x^3/3- x^4/4+x^5/5- * * * #

    After you find #ln n#, use division to get #log_10 n ~~ ln n / 2.302585093#

  • This key question hasn't been answered yet. Answer question
  • This key question hasn't been answered yet. Answer question

Questions