Paper 3, Section I, H

Number Theory
Part II, 2015

What does it mean to say that a positive definite binary quadratic form is reduced? Find the three smallest positive integers properly represented by each of the forms f(x,y)=3x2+8xy+9y2f(x, y)=3 x^{2}+8 x y+9 y^{2} and g(x,y)=15x2+34xy+20y2g(x, y)=15 x^{2}+34 x y+20 y^{2}. Show that every odd integer represented by some positive definite binary quadratic form with discriminant 44-44 is represented by at least one of the forms ff and gg.