logarithms

• sammiegal

  2 Apr 06, 19:57

  indices, surds & logarithms test tmr and I don't have a clue how to change the bases of logarithms.. help? i don't understand the textbook meaning- it doesnt make sense.
• FireIce

  2 Apr 06, 19:58

  
• CoolMyth

  2 Apr 06, 20:01

  Originally posted by FireIce:

  

  And the proof:
  
  Let log(a) x = y
  
  --> a^y = x
  
  Take base b on both sides:
  
  --> y log(b) a = log(b) x
  
  --> y = [log(b) x]/[log(b) a]
  
  
• mystiv

  2 Apr 06, 20:02

  guess there's nothing left for me to explain
• sammiegal

  2 Apr 06, 20:10

  o..k.. thanks.
  
  now.. all i hafta do is understand it.
• FireIce

  2 Apr 06, 20:11

  maths is mostly about practise
• CoolMyth

  2 Apr 06, 20:14

  Originally posted by sammiegal:

  o..k.. thanks.
  
  now.. all i hafta do is understand it.

  You can practice using values on your calculator, with any number you chose and then using the common bases e and 10.
  
  You'll see the answer on both sides match up.
• sammiegal

  3 Apr 06, 20:45

  on a side note, i'm rather sure i failed the abovemention a maths test. cheers.