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# LOGARITHMS

CONTENT

1. Deducing logarithm from indices and standard form
2. Definition of Logarithms
3. Definition of Antilogarithms
4. The graph of y = 10x
5. Reading logarithm and Antilogarithm tables

## Deducing Logarithm From Indices and Standard Form

There is a close link between indices and logarithms

100 = 102. This can be written in logarithmic notation as log10100 = 2.

Similarly 8 = 23 and it can be written as log28 = 3.

In general, N = bx in logarithmic notation is LogbN = x.

We say the logarithms of N in base b is x. When the base is ten, the logarithms is known as common logarithms.

The logarithms of a number N in base b is the power to which b must be raised to get N.

Re-write using logarithmic notation (i) 1000 = 103 (ii) 0.01 = 10−2 (iii) 24 = 16 (iv) 1/8 = 2−3

Change the following to index form

(i) $$Log_416 = 2$$

(ii) $$Log_3 (\frac{1}{27}) = -3$$

The logarithm of a number has two parts and integer (whole number) then the decimal point.

Lesson tags: General Mathematics Lesson Notes, General Mathematics Objective Questions, SS1 General Mathematics, SS1 General Mathematics Evaluation Questions, SS1 General Mathematics Evaluation Questions First Term, SS1 General Mathematics First Term, SS1 General Mathematics Objective Questions, SS1 General Mathematics Objective Questions First Term
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