1 outside

There are many special numbers, such as π: 3.14159265 ... wiki: zh. *** /w/index？ Title =% E5% 9c% 93% E5% 91%A8% E7% 8e% 87&; Variant = zh-e: 2.182818 ... Wiki especially related to calculus. * * */w/index？ Title = E _% 28% E6% 95% B0% E5% AD% A6% E5% B8% B8% E6% 95% B0% 29&; Variant = zh-φ: 0.6 18 ... or 1.6 18 ... which is the golden ratio wiki: zh. *** /w/index？ Title =% e9% bb% 83% e9% 87% 91%E6% AF% 94% E4% Be% 8B&; Variant=zh- The most famous one should be based on three 2008-08-0516: 27:17 supplements: there is one in China.

I

Definition I 2 =-1+0

Does not exist

But a meaningful number.

Reference: I+Wiki

I think the most interesting is "0"&; "1" says 0 0 first, which can be said to be the only one among all intermediate numbers. Generally speaking, the system of positive and negative numbers is nothing, but it is an important dividing line between positive and negative in science. There is a limit to the quantity.

As long as one is 0, the answer will be 0. Let 1 1 be a natural number. The multiple of 1 1 is 1. What is the multiple of 1? The mathematician Pythagoras said, 1 produces 2.

2 students 3

The importance of 1 can be seen in the biology 2008-08-05 20: 41:41Supplement: π e φ should not be a number but the number (digits) is 0.

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9, 10, 2008-08-05, 20: 43: 00 Supplementary:-1 to -9, but I don't know if it is a number.

Reference: I

The olympiad math teacher said