Re: no results with 'InequalitySolve'
- To: mathgroup at smc.vnet.net
- Subject: [mg42367] Re: no results with 'InequalitySolve'
- From: "Dana DeLouis" <delouis at bellsouth.net>
- Date: Wed, 2 Jul 2003 06:36:29 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hello. In Mathematica 5, I seem to get a good approximation, along with the standard warning message: Needs["Algebra`InequalitySolve`"] InequalitySolve[Sin[x] > 0.5, x] InequalitySolve::npi:A nonpolynomial equation or inequality encountered. The \ solution set may be incorrect. x > 0.5235987755982989 The Sin of this value does appear to be equal to 0.5 Sin[0.5235987755982989] 0.5 Slightly better is to make the 0.5 more exact (1/2) InequalitySolve[Sin[x] > 1/2, x] x > Pi/6 However, I seem to get a "better" approximation with Reduce: Reduce[Sin[x] >= 1/2 && 0 <= x <= 2*Pi, x] Pi/6 <= x <= (5*Pi)/6 A check on its value... Sin[Pi/6] 1/2 HTH. -- Dana DeLouis Windows XP Mathematica $VersionNumber -> 5 delouis at bellsouth.net = = = = = = = = = = = = = = = = = "Oliver Kowalke" <oliver.kowalke at t-online.de> wrote in message news:bds0i9$62b$1 at smc.vnet.net... > Hi, > > I've Mathematica 4.1 on Linux. If I try to solve this: > > InequalitySolve[Sin[x] > 0.5, x] > > Mathematica recalls it without solving it. Why? What do I've to do? > > thx, > Oliver >