(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let G be group, H<G , K<G, if gcd(lHl,lKl)=1, prove that H[tex]\bigcap[/tex]K={1}

2. Relevant equations

3. The attempt at a solution

so Lagrange theorem says that lHl l lGl, lKl l lGl,

and of course 1 is inside both H and K, but how when they are coprime, the element are all different except their identity? i cannot see T_T

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# Homework Help: Lagrange theorem and subgroup help

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