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Exponentials and Logarithms

Now for logarithms.  What was that sound?  Was that your intestines knotting up?  Ah, come on!  Logarithms are easy...  IF you know what they are.

Logarithms are inverses of exponentials!

Inverse functions undo each other, so logs just undo exponentials.  You did this when you used logs to solve exponential equations.  That's all.  Nothing scary.


The inverse of		f( x ) = 2^x ... Base 2
is		f^( -1 ) = log base 2( x ) ... Base 2

Other pairs:

f( x ) = 10^x and f^( -1 ) = log( x ) ... really log base 10( x )

 

f( x ) = e^( x ) and f^( -1 ) = Ln( x ) ... really log base e( x )