prove or disprove

For z=(-1)^y, y is irrational, z is not a real number.

More generally,
For z=x^y with x<0 and y is irrational, z is not a real number.

所有跟帖： 

• 回复：prove or disprove -hisch8- ♂ (63 bytes) () 09/22/2009 postreply 09:34:53

• 回复：回复：prove or disprove -yma16- ♂ (70 bytes) () 09/22/2009 postreply 16:34:52

• Thanks -yma16- ♂ (72 bytes) () 09/23/2009 postreply 07:03:53

• 回复：Thanks -yma16- ♂ (30 bytes) () 09/23/2009 postreply 07:06:43