RE: Intersection of sets of results
- To: mathgroup at smc.vnet.net
- Subject: [mg37113] RE: [mg37099] Intersection of sets of results
- From: "DrBob" <drbob at bigfoot.com>
- Date: Thu, 10 Oct 2002 03:20:46 -0400 (EDT)
- Reply-to: <drbob at bigfoot.com>
- Sender: owner-wri-mathgroup at wolfram.com
Those aren't equations; they're functions, and we don't solve functions, we solve equations. What equations do you want to solve? DrBob -----Original Message----- From: flip [mailto:flip_alpha at safebunch.com] To: mathgroup at smc.vnet.net Subject: [mg37113] [mg37099] Intersection of sets of results Hello All, I have two equations that I have solved for: x[n_] := 2331 + 8 n y[n_] := -3108 - 11n I want to include only solutions which are non-negative, that is x >= 0 and y >= 0. In this example we can do 2331 + 8n > = 0 and solve for n, n >= -291.375 and -3108 - 11 n >= 0 and solve for n, n <= -282.545 So we have -291.375 <= n <= -282.545. The "integer solution set here is for n = {-290, -289, -288, -287, -286, -285, -284, -283}. So in this case we have 8 non-negative solutions. Given that I can supply x[n] and y[n], how do I go about finding the set n? Thank you for any inputs, Flip