Why log is not defined for negative values?

Related questions

1. What number has the natural logarithm of?
2. What is the relation between log and ln?
3. Can you take Ln of 0?
4. Is Ln 0 defined?
5. What is the difference between log and ln?
6. How do you undo LN?
7. What is the relationship between log and ln?
8. Is log10 the same as LN?
9. What is Ln of a number?

Tags

1. #positive
2. #always
3. #something
4. #exponent
5. #power
6. #infinity
7. #number
8. #raised
9. #value
10. #negative
11. #since
12. #approaches
13. #least
14. #exponential
15. #would
16. #attain
17. #never
18. #function