Question

If sqrt(x) is rational, then x is rational. Prove.

Answer 1

If x is rational\[\exists a,b (x = \frac{a}{b})\] Then\[x^{2} = \frac{a^{2}}{b^{2}}\]
QED

Answer 2

oh yeah a and be are integers a and b are both positive or both negative, b not equal zero

Answer 3

The questions If the square root of x is rational, then x is rational.. You just proved that if x is rational so is x squared.

Answer 4

just change the x to sqrt(x) and the proof is still valid.