User david - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-23T02:05:23Z http://mathoverflow.net/feeds/user/19240 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/80874/why-polynomial-gxx-2-x-has-exactly-has-two-roots-in-any-ring-of-the-form-z-p why polynomial g(x)=x 2 −x has exactly has two roots in any ring of the form Z p r david 2011-11-14T07:10:33Z 2011-11-14T07:10:33Z <p>why polynomial g(x)=x 2 −x has exactly has two roots in any ring of the form Z p r</p> http://mathoverflow.net/questions/80871/how-many-idempotent-elements-are-in-z-m How many idempotent elements are in Z_m david 2011-11-14T06:39:23Z 2011-11-14T06:47:37Z <p>How many idempotent elements are in Z_m or How many roots have this polynomial in Z_m</p> <p>f(x)=x^2 +x procedure of proof is important for me.</p> http://mathoverflow.net/questions/80871/how-many-idempotent-elements-are-in-z-m/80872#80872 Comment by david david 2011-11-14T07:05:29Z 2011-11-14T07:05:29Z why polynomial g(x)=x 2 −x has exactly has two roots in any ring of the form Z p r ?