challenge for trigsimp
- Subject: challenge for trigsimp
- From: Edwin Woollett
- Date: Tue, 29 Sep 2009 10:24:35 -0700
On Sept. 28, Richard Fateman wrote:
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cos(y+2*x)+2*sin(x)*sin(y+x)-cos(y)
trigsimp(%) ;; no change
trigreduce(%) ;; changed
ratsimp(%) ;; produces zero.
poissimp produces zero right away.
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If a multiple term trig function expression should
equal zero, I like trigrat.
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(%i1) e : cos(y+2*x)+2*sin(x)*sin(y+x)-cos(y)$
(%i2) poissimp (e);
(%o2) 0
(%i3) trigrat (e);
(%o3) 0
(%i4) trigreduce (e), ratsimp;
(%o4) 0
(%i5) ( ev(trigexpand (e),trigexpand,expand),trigsimp(%%));
(%o5) 0
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Ted Woollett