Question

Prove that ∛(2) + √(3) is an algebraic number. (SOLUTION INCLUDED.)

Problem and solution:
http://www.tiikoni.com/tis/view/?id=aefc6d6

I just wanted to ask/confirm if the solution made a mistake, such that

x^6 - 9x^4 - 4x^3 + 27x^2 + 36x - 23 = 0

should be

x^6 - 9x^4 - 4x^3 + 27x^2 - 36x - 23 = 0

instead. (Notice the -36x instead of +36x.)


Any input would be greatly appreciated!

Answer 1

Wolfram Alpha confirms that it should be a -36x.

Answer 2

Thanks for confirming @KingGeorge!