## Monday, 8 December 2008

### Common "log" mistake

Teacher: John, can you give the answer for X in this log X = log 6 question?

John: No problem. The value for X is simply 6.

Teacher: Correct! How did you get the answer?

John: It is easy. Just do it this way
(John wrote on the board). ==> X = (log 6) /log ==>X = 6.

Teacher: ?????

************************* What happened? ***********************

Logarithm or "log", in its abbreviated form, can be easily misunderstood.

What is this "log"?

Logarithm is an operation on a number that is the reverse of that for indexing a number.

LogaX = Y ==> aY = X

From the above relationship, you will notice that "log" itself cannot stand alone.

That means "log" must come with a number or expression.

"Log" is an operator, like the "+" or "-".

John mis-interpreted the "log" to be a variable!

It made him transfer the "log" over the equal symbol as though it is a number (or equivalent).
the "log" is thus, separated from the "X" that it should operate upon.

A common "log" mistake was made.