(a) Using quadratic reciprocity determine which primes are represented by some form of discriminant 17.
(b) Show that all forms of discriminant 17 are equivalent to the form x2+xy−4y2.
(c) Draw enough of the topograph of x2+xy−4y2 to show all values between −70 and 70, and verify that the primes that occur are precisely the ones predicted by your answer in part (a).