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Euler $\Phi$ Function

$$\underline{Question}$$ Compute $\phi(24)$. For each element $\mathbb Z /24$ decide whether the element is a unit or a zero divisor. If the element is a unit, give its order and find its inverse.

$$\underline {Answer}$$ let $\,\,n=24=2\cdot3\cdot 3 \,\,,\, (\mathbb Z /24)$ ={$\bar1,\bar5,\bar7,\bar11,\bar13,\bar17,\bar19,\bar23$}

$\phi(24)=8$

How would i go about deciding whether each of the elements are a unit or zero divisor?

  • 0
    What does $24=2.3.3(\Bbb Z/24)$ mean?2012-11-29
  • 4
    Looks like one of your classmates is on Math.SE too. http://math.stackexchange.com/questions/246440/euler-phi-function2012-11-29

2 Answers 2