1 (one)
In many situations the number 1 is omitted, but it is there anyway.
Explanation
When enumerating
you say a, two a, three a, but you don't start with one a. You can write 1a however. By exponentiation you get
where you then say a, and a square, and a cube. And not a to the power one, and a to the power two. You can write a1, and even 1a1, but that is never done. You can also write
For solving
you must first multiply the denominators with each other, and afterwards the numerators. So you must find a numerator for the 6, and of course you take 1 as
In a fraction you can divide the denominator and the numerator by the same number. Here you see
There remains 1 in the numerator, and this time you must write that. Don't call it delete, then you make a division. Now let us take the equation
This is correct, but it doesn't imply that 2 is equal 3. For every number a ≠ 0 applies a0 = 1. That works of course also for the number 1, so
and even for
It looks quite strange. We can easily check this, and find
Mind however
Example 1
A calculation with the number π gives
Example 2
You can also calculate with the number e
Example 3
You can write √2 as 1√2 and so is