Path: csiph.com!news.mixmin.net!weretis.net!feeder1.news.weretis.net!newsfeed.CARNet.hr!news.spin.it!bofh.it!news.nic.it!robomod From: Walter Lenzenweger Newsgroups: linux.debian.maint.java Subject: GeoGebra - bug report Date: Sun, 23 Aug 2015 02:40:01 +0200 Message-ID: X-Original-To: debian-java@lists.debian.org X-Mailbox-Line: From debian-java-request@lists.debian.org Sun Aug 23 00:33:09 2015 Old-Return-Path: X-Amavis-Spam-Status: No, score=-0.146 tagged_above=-10000 required=5.3 tests=[BAYES_40=-0.01, FSL_HELO_BARE_IP_2=2, RCVD_IN_DNSWL_MED=-2.3, RCVD_NUMERIC_HELO=1.164, RP_MATCHES_RCVD=-1] autolearn=no autolearn_force=no X-Policyd-Weight: NOT_IN_SBL_XBL_SPAMHAUS=-1.5 NOT_IN_BL_NJABL=-1.5 CL_IP_EQ_HELO_IP=-2 (check from: .uibk. - helo: .lmr1.uibk. - helo-domain: .uibk.) FROM/MX_MATCHES_HELO(DOMAIN)=-2; rate: -7 X-Greylist: delayed 854 seconds by postgrey-1.35 at bendel; Sun, 23 Aug 2015 00:16:30 UTC MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) H3 (4.3.11) X-Originating-IP: 138.232.2.96 X-Forwarded-For: 193.81.123.106 X-Scanned-By: MIMEDefang 2.75 at uibk.ac.at X-Mailing-List: archive/latest/18593 List-ID: List-URL: List-Archive: https://lists.debian.org/msgid-search/20150823020212.53513ac0k8m300hw@web-mail.uibk.ac.at Approved: robomod@news.nic.it Lines: 33 Organization: linux.* mail to news gateway Sender: robomod@news.nic.it X-Original-Date: Sun, 23 Aug 2015 02:02:12 +0200 X-Original-Message-ID: <20150823020212.53513ac0k8m300hw@web-mail.uibk.ac.at> Xref: csiph.com linux.debian.maint.java:8281 Dear Ladies and Gentlemen! I have discovered two problems with the GeoGebra-command Tangent: 1. By chance I acchieved to construct a tangent from a point which does NOT lie on the curve, but the parameter-options for the command Tangent only contain Tangent[Point on Curve, Curve] (1) not Tangent[point, curve]! (2) 2. While Tangent works for purpose (2), it does not work for purpose (1) - for implicit curves at least: I have considered an implicit curve (algebraic curve, order 3), a point P in the plane and the tangent from P to c. A = 1 B = 1 P=(-2,1) c: A x³ + B y = 0 t = Tangent[P,c] I see 4 tangents to c through P, but if I change P to (0,0), save the file,reopen it, two windows appear saying: 'opening file failed' and a new ggb-window is opened but I cannot open the saved file! Of course it would be easy to solve this problem defining explicitely f(x) = -x^3 instead of c, but I am interested in tangents in given points of any algebraic curve which cannot be defined explicitely! Best wishes and thanks for clearing this problem! Walter Lenzenweger P.S. I am using a Dell-notebook XPS L502X, Windows 7