# Manuals/calci/LOG

LOG (Number,Base)

• is a positive real number and
•  is the base of the logarithm.
• LOG(), returns the logarithm of a number to a specified base.

## Description

LOG(Number,Base)

For Example,

LOG(10, 2) returns 3.3219280948873626

LOG(100,10) returns 2

LOG(4, 0.5) returns -2

• The should be a positive real number. Else Calci displays NaN error message.
• The should be a positive real number. Else Calci displays NaN error message.
• If the is omitted, Calci assumes it to be 10.
• LOG() can be used in an equation as -

LOG(LOG(10,2),3) + LOG(10,2) returns 4.414711580210549

• The function can be used to find the logarithm of array of numbers with a specified base.

e.g. LOG(10..15, 2) that displays the output as below -

n base LOG Output
10 2 3.3219280948873626
11 2 3.4594316186372977
12 2 3.5849625007211565
13 2 3.700439718141092
14 2 3.8073549220576037
15 2 3.9068905956085187

## Examples

 10 2 50 10 7.5 7.5 120 700
```=LOG(A1,B2)  : Calculates the logarithm of 10 with base 10. Returns 1 as a result.
=LOG(A4:A5,B1)  : Calculates the logarithm of values 120, 700 with base B1 (2).Returns 6.906890595608519, 9.451211111832329 as a result.
=LOG(A4)  : Calculates the logarithm of 120. Here base is assumed to be 10. Returns 2.0791812460476246 as a result.
=LOG(100,B3)  : Calculates the logarithm of 100 with base 7.5. Returns 2.2855542619359994 as a result.
```

LOG