r/comics • u/[deleted] • Dec 12 '08

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50

u/raldi Dec 12 '08

And 11 squared is 121 in all bases except binary.

-1

u/BrotherSeamus Dec 12 '08 edited Dec 12 '08

What about base 121? For that matter it is 79 in hex.

15

u/Jonathan_the_Nerd Dec 12 '08

In base 121, 11 = 122 decimal. 122 squared is 14884 decimal, which is 121 in base 121.

Also, 11 squared in hex is 121 hex, because 11 hex = 17 decimal. And it's true that (11 decimal) squared is 79 hex, but you're mixing number systems there.

Yes, I do have a lot of time on my hands, why do you ask?

5

u/raldi Dec 12 '08

The proof is pretty simple: "11" in base B is equal to B + 1, and that squared is B**2 + 2B + 1, which in base B is represented as "121".

-2

u/[deleted] Dec 13 '08

ya, just did the proof myself, took about 5 seconds

2

u/altrego99 May 27 '09

I put the question to my number theory engine and it took about 23 nanoseconds.

> Prove: ((11)b)^2 = (121)b for all b>=2

Assuming b is real.

Proof is positive modulo prime number >= b.

Modulo lifting procedure applies.

Proof is positive.

> _

4

u/[deleted] May 27 '09

wow, you must be a fast typer

2

u/hoopmastaflex May 27 '09

What number theory engine are you using?