Recent content by Marcio reis

Thanks! It's proved somewhere else that Z[X] and the multiplicative group of positive rational numbers are isomorphics. I was wondering why the negative rational numbers must be excluded.

Z[X] is the additive group and Q is the multiplicative group of all rational numbers without zero.

How did you find PF?: https://www.intmath.com/blog/learn-math/top-10-math-help-sites-5966 Hello everyone. I know that there is a group isomorphism from Z[X] to the multiplicative group of all positive rational numbers. My question is: Are Z[X] and Q isomorphic groups?