# Omega

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bio website location age 19 member for 3 years, 1 month seen 2 days ago profile views 170

# 339 Actions

 Dec7 asked What is wrong with my polynomial division? $x^3-2x^2-5x+6$ Dec7 accepted How to verify if $aRb \leftrightarrow a - b \le 10$ is total? Dec7 accepted How was $f(x) = -2x-1$ found in this system? Dec7 accepted How do I solve inequalities of the form $\frac{ax}{b}\geq0$? Dec7 asked How was $f(x) = -2x-1$ found in this system? Dec7 comment How do I solve inequalities of the form $\frac{ax}{b}\geq0$? @MhenniBenghorbal: Yeah, I'm not sure why was I calling it maximum domain... Dec7 asked How do I solve inequalities of the form $\frac{ax}{b}\geq0$? Dec7 asked How to solve systems of three equations? Dec6 comment How can I prove that if a relation is symmetric then its inverse is also symmetric? ... I'm not gonna lie - I am having trouble with "If $R$ is transitive, then $R \cap R^{-1}$ is transitive." - Not very sure how to work with this $\cap$... Any ideas? Dec6 comment How can I prove that if a relation is symmetric then its inverse is also symmetric? Well, it is in spanish, "Introduction to Discrete Mathematics" ("Introduccion a la Matematica Discreta") by Manuel Murillo Tsiji Dec6 comment How can I prove that if a relation is symmetric then its inverse is also symmetric? Well that was silly... thanks a lot! I guess the other exercises are similar to this. Dec6 accepted How can I prove that if a relation is symmetric then its inverse is also symmetric? Dec6 comment How can I prove that if a relation is symmetric then its inverse is also symmetric? Hm..., so I could do something like... $$(aRb \implies bRa) \implies (bR^{-1}a \implies aR^{-1}b)$$ and then... I'm done since this proves that $R^{-1}$ is symmetric? Dec6 accepted How to “make up a formula” of a sum? Dec6 asked How can I prove that if a relation is symmetric then its inverse is also symmetric? Dec6 comment How to verify if $aRb \leftrightarrow a - b \le 10$ is total? I can see it is true, yes, definitely true - but I need to prove it in a formal manner. I doubt that showing a bunch of examples would work. Dec6 comment How to verify if $aRb \leftrightarrow a - b \le 10$ is total? @peoplepower: It would mean... $a - b > 10$? I still don't see the point :( Dec6 comment How to verify if $aRb \leftrightarrow a - b \le 10$ is total? I do know the definition of total - but I don't know how to prove it (which is precisely what I'm asking here). Dec6 asked How to verify if $aRb \leftrightarrow a - b \le 10$ is total? Dec6 accepted If $aRb \land bRc$ never occurs, is a relation considered transitive?