"Prove or disprove that if a and b are rational numbers, then a^b is also rational."

a = s/r, b = c/d.

(s/r)^(c/d)

(s^(c/d)) / (r^(c/d))

Now I am back where I started. Both the numerator and denominator is a rational number raised to a rational number. I'm not even sure If I am taking the right approach. Please help, thank you.