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Logarithms

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Definition of a Logarithm:

If y = bx, then the logarithm, to the base b of a positive number is denoted by logb y and is defined by logb y = x.

And so, if 9 = 32, then the logarithm to the base 3 of 9 is defined by log3 9 = 2.

DON’T BE INTIMIDATED BY LOGARITHMS! ! ! Use this flashcard drill to become a master of logarithm basics.

CLICK HERE TO PRACTICE LOGS WITH VARIABLES

  • log2 2 =
    1
  • log2 4 =
    2
  • log2 8 =
    3
  • log2 16 =
    4
  • log2 32 =
    5
  • log2 64 =
    6
  • log2 128 =
    7
  • log2 256 =
    8
  • log2 512 =
    9
  • log2 1024 =
    10
  • log3 9 =
    2
  • log3 27 =
    3
  • log3 81 =
    4
  • log3 243 =
    5
  • log3 729 =
    6
  • log3 2,187 =
    7
  • log4 16 =
    2
  • log4 64 =
    3
  • log4 256 =
    4
  • log4 1024
    5
  • log5 25 =
    2
  • log5 125 =
    3
  • log5 625 =
    4
  • log5 3,125 =
    5
  • log2 (1/4) =
    -2
  • log2 (1/8) =
    -3
  • log2 (1/16) =
    -4
  • log2 (1/32) =
    -5
  • log3 (1/9) =
    -2
  • log3 (1/27) =
    -3
  • log3 (1/81) =
    -4
  • log3 (1/243) =
    -5
  • log4 (1/16) =
    -2
  • log5 (1/25) =
    -2

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