This adjective denotes a type of imaginary field of which there exist nine with unique factorization, which is the “n equals one” case of the class number problem. An integer x is a type of number denoted by this adjective with respect to a prime p if and only if x to the “p-minus-one over 2” is congruent (-5[1])to one mod p, by Euler’s criterion. A result with this adjective in its name concerns the Legendre symbol of “p over q” times the Legendre symbol of “q over p.” That theorem about modular congruences, which can be used to find “residues” described by this adjective, was proved (10[1])by Gauss and is named for this type of “reciprocity.” This adjective denotes a formula whose discriminant is “b-squared minus 4 (10[1])a c.” (10[1])For 10 points, what adjective denotes polynomials whose leading term is x-squared? ■END■ (10[1])