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PrudensOptimus
Dec2-03, 05:07 PM
Hi, is there any way to find Unit Digit of a expression, say

a^b


where a, b, are positive integers?

Hurkyl
Dec2-03, 06:05 PM
Yes.

Hint: fix a, vary b, and ignore the irrelevant details, see if you can find a clue...

PrudensOptimus
Dec2-03, 06:08 PM
U mean a pattern?

Like 2^2 = 4, like 2^2222 = 4? Because 2222 is divisible by 2?

Hurkyl
Dec2-03, 06:23 PM
I mean something a little more rigorous. [:)]

Consider the values of 2^1, 2^2, 2^3, ...