I've a couple of problems that are driving me crazy:
Prove or disprove that if a,b ε D and a > b, then a² > b².
Prove or disprove that if a,b ε D and a > b, then a³ > b³.
Should I start with a² > b² and try and disprove it for a²=b², and a² < b²? I have been trying it that way but no success as of yet.
Any help would be much appreciated.