From: SourceForge.net <noreply@so...>  20030524 22:27:46

Bugs item #742909, was opened at 20030524 18:27 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=742909&group_id=4933 Category: None Group: None Status: Open Resolution: None Priority: 4 Submitted By: Stavros Macrakis (macrakis) Assigned to: Nobody/Anonymous (nobody) Summary: trigrat(sin(x/2)) makes a mess Initial Comment: trigrat(sin(x/2)) => (%I*(SIN(x/2)*SIN(x)+COS(x/2)*COS(x)COS(x/2)) COS(x/2)*SIN(x)+SIN(x/2)*COS(x)SIN(x/2))/(2*SIN(x/2) ^2+2*COS(x/2)^2) Although this is correct, I doubt that this is what trigrat is supposed to do. After all, it has not eliminated sin (x/2); the result contains sin(x/2), but also contains sin^2+cos^2, so it doesn't seem "more linear" in any sense. Also, it is not a canonical form: trigrat(ev(sin (x/2),halfangles)) gives something else (even messier). Note also that sin(2*x) does not expand in trigrat.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=742909&group_id=4933 