好心人帮帮2005回忆题。。怎么办啊。。前天才开始复习。。三天就要考了~

TotengUID: 2124650

若aba=1
由群的结合律有
a(ba)=1=(ab)a
又由逆元唯一
ba=ab

同问A……

kainwilliamUID: 2135234

klein群？

icewolfUID: 2146015

第一题：
consider f(z)=e^z as a function from R^2 to R^2, then f is continous. By the results that the image of a connected set by a continous function is connected, we know the nember of connected component is 1.