- #1
srfriggen
- 307
- 6
Homework Statement
Use the rational roots theorem to prove 31/2-21/3is irrational.
The Attempt at a Solution
My teacher strongly hinted to us that this problem had something to do with the fact that complex roots come in conjugate pairs, and all we had to do was, "flip the sign". But there isn't anything complex about this.
I was trying to work it out by setting x=31/2-21/3and trying to get rid of the fractional exponents by squaring or cubing, but I can't get the algebra down to get that to work.