Indices, Surds & Logarithms

 

 

Contents

 

Indices

 

Laws of Indices

 

Surds

 

Laws of Surds

 

Exponential Equations

 

Logarithms

 

Laws of Logarithms

 

Logarithmic Equations

 

Quiz

 

Algebra Main Page

Indices
 
 
Imagine you have a piece of paper. You tear it into two. You then proceed to tear both pieces again into another two. Now, you have 4 pieces of paper. If you tear it a third time, how many pieces would you have? What about 6 times? What about fifteen times?
 
Based on what you already know, tearing it a third time would give you:
                             2 x 2 x 2 = 8 pieces.
The sixth time would give you:
             2 x 2 x 2 x 2 x 2 x 2 = 64 pieces.
 
Writing 2 x 2 x 2 x 2 ... endlessly is not only time consuming, but also a waste of space as well as impractical. So how can we shorten it?
 
 
This is where indices come in. Simply, an index is written in the form:
                                       ab
where a is the base and b is the index. ab basically means:
           ab = a x a x a x a ... x a (b times)
 
Referring to the above example,
        3rd time will give you 23 = 2 x 2 x 2 = 8 pieces,
        6th time will give you 26 = 2 x 2 x 2 x 2 x 2 x 2 = 64 pieces,
   and the 15th time will give you 215 = 32768 pieces.
 
 
Indices are generally large numbers. How large, you may say. Take a paper-tearing example. Assuming the paper is 0.05 mm thick, if you tear it 20 times and stack all the pieces on top of each other, the height of the paper is similar to the depth of a swimming pool. And if you tear it 42 times and stack them all up, you can reach the moon.