Xkalibur wrote:krisi wrote:Xkalibur,
Do you want a numerical value to prove it?
No, there's no need for it. I'll show you how to do that in a logical way.
A- is a rational number.
B- is an irrational number.
A+B or A-B
1. Let's presume that sum A+B is a rational number:
2. If so, then B:
B=C-A would have been also rational as the difference of two rational numbers, but isn't so because it contradicts to the statement (B- an irrational number). Thus, our presumption was false and therefore sum A+B is an irrational number.
(A-B is similar to the above.)
Simple, isn't it?
Yes, yes. Got it!