Categories

# Logarithm of numbers (Index & Logarithmic Form)

The logarithm to base a of a number P, is the index x to which must be raised to be equal to P.

Thus if P = ax, then x is the logarithm to the base aof P. We write this as x = log a P. The relationship logaP = x and ax=P are equivalent to each other.

ax=P is called the index form and logaP = x is called the logarithm form

## Easy way to learn Logarithm Basics Click interactive slideshow

https://www.slideshare.net/slideshow/embed_code/key/eKcMhM60XKWiyBLogarithm from Bangladesh University of Professionals

### Conversion From Index to Logarithmic Form

Write each of the following index form in their logarithmic form

1. a) 26 = 64 b)            251/2 = 5                               c)  44= 1/256

Solution

1. a) 26 = 64

Log2 64 = 6

1. b) 251/2 = 5

Log255=1/2

1. c) 4-4= 1/256

Log41/256 = -4

### Conversion From Logarithmic to Index form.

1. a) Log2128 = 7 b)            log10 (0.01) = -2
2. c) Log5 2.25 = 2

#### Solution

1. a) Log2128 = 7

27 = 128

1. b) Log10(0.01) = -2

10-2= 0.01

1. c) 5 2.25 = 2

1.52 = 2.25