Question 15
Determine all nonconstant monic polynomials with integer coefficients
$$X^n+a_1X^{n-1}+\cdots+a_{n-1}X+a_n$$
whose roots are exactly $a_1,\ldots,a_{n-1},a_n$, counted with multiplicity.
$$X^n+a_1X^{n-1}+\cdots+a_{n-1}X+a_n$$
whose roots are exactly $a_1,\ldots,a_{n-1},a_n$, counted with multiplicity.