Let E be the set of real numbers, x, satisfying ax^2+bx+c=0 for some a,b,c in Z Show that E is countable.
Follow Math Help Forum on Facebook and Google+
Originally Posted by ashamrock415 Let E be the set of real numbers, x, satisfying ax^2+bx+c=0 for some a,b,c in Z Show that E is countable. The cross product of two countable sets is countable. There can be at most two distinct real solutions per (a,b,c). The cardinality of E is at most the cardinality of Z x Z x Z x {0,1}.
View Tag Cloud