- #1
annoymage
- 362
- 0
Homework Statement
Let G be group, H<G , K<G, if gcd(lHl,lKl)=1, prove that H[tex]\bigcap[/tex]K={1}
Homework Equations
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