Mammoth Memory

Logarithms                                                                

Whenever you see the words log or logarithms write down the following:

 `Log_2(8)=3`

And write down

What is the power on 2 that gives 8 

Logs explained                                                          

`Log_2(8)=3`

This says:

What is the power on 2 that gives 8

`2^? = 8`

The only answer is 3

i.e. `2^3 = 8`

 

For any log

From the above `Log_ab`

Logarithm is the power on “`a`” that gives the result “`b`”

 

Examples

1.  What is `Log_3 81`

So always write down `Log_2 (8) = 3`

And write “what is the power of `2` that gives `8`” (answer `3`)

Therefore  `Log_3 81`

This says what is the power on `3` that gives `81`

`3^?` `= 81`
`3times3` `= 9`
`3times3times 3` `= 27`
`3\times 3\times 3\times 3` `= 81 (4\ t\im\es)`

Therefore Answer: `4` is the power on `3` that gives `81`

That is `3^4 = 81`

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