Logarithm eqns

• donkhead333

  3 Dec 08, 10:17

  1/2log2(5) + log4(0.4) + log1/2(25)

  Evaluate this logarithimic expression..

  got stuck with the log4(0.4) and started to work about in circles >.<

  numbers in brackets are not subscript

• eagle

  3 Dec 08, 10:41

  To evaluate, use your calculator
  ½log₂(5) + log₄(0.4) + log_½(25) = -4.144

   

  If it is to simplify:

  ½log₂(5) + log₄(0.4) + log_½(25)

  = ½log₂(5) + log₄(2/5) + log_½(5²)

  = ½log₂(5) + [log₂(2/5)] / log₂(4)+ [log₂(5²)] / log₂(½)

  = ½log₂(5) + [log₂(2) - log₂(5)] / 2 + 2log₂(5) / (-1)

  = ½log₂(5) + ½log₂(2) - ½log₂(5) - 2log₂(5)

  = ½log₂(2) - 2log₂(5)

  = ½  - 2log₂(5)

   

• 190

  30 Dec 08, 18:51

• 190

  30 Dec 08, 19:01