I notice that there is such an expression "1e-5" in Python(probably in other languages also)

  1. What is the name of this notation?

  2. what does it denote in math?

  3. What does 'e' mean? It's the first time I see a character helps to denote some value, are there other characters also help do so?

  4. Why should use this way instead of some other python math operation like pow() etc.

2

3 Answers

It is scientific notation. It means 1 × 10−5. In other words, 0.00001.

2

10 ** -5, i.e. 10 to the power of negative 5, 1 divided by 10 to the power of 5, or 0.00001.

It means 10 to the power of -5 times 1