Hello,
I am having some problem with computing a dot products. It is probably something simple that I am not seeing it. Some of the lines are redundant but I am keeping it because the problem shows up. The dot product is supposed to be zero but I get different number (last line). Thank you.
wxMaxima 0.7.3a http://wxmaxima.sourceforge.netMaxima 5.13.0 http://maxima.sourceforge.netUsing Lisp GNU Common Lisp (GCL) GCL 2.6.8 (aka GCL)Distributed under the GNU Public License. See the file COPYING.Dedicated to the memory of William Schelter.This is a development version of Maxima. The function bug_report()provides bug reporting information.
Here is the code
/** ------------------------------------------------------------------------------------------------------------------ **/
keepfloat:true;
sol2:[[1,-(sqrt(4*t^2+q^2-2*p*q+p^2)-q+p)/(2*t),0],
[-1,-(sqrt(4*t^2+q^2-2*p*q+p^2)+q-p)/(2*t),0]];
print("dot product of 2 vect in sol2");
radcan(sol2[1].sol2[2]);
print("make trig substitution")$
EA2:ratsubst(1.0-sin(th)^2,cos(th)^2,ev(sol2));
v1:EA2[1]$
v2:-EA2[2]$
p:192.6988*sin(th)^2+4.9619*cos(th)^2$
q:4.9619*sin(th)^2+8.0665*cos(th)^2$
r:4.9619*sin(th)^2+2.4489*cos(th)^2$
t:-7.69*cos(th)*sin(th)$
radcan(ev(v1.v2));
ratsubst(%pi/3,th,ev([v1.v2]));
/** Output **************************************************************************/
(%o1) true(%o2) [[1,(-sqrt(4*t^2+q^2-2*p*q+p^2)+q-p)/(2*t),0],[-1,(-sqrt(4*t^2+q^2-2*p*q+p^2)-q+p)/(2*t),0]]dot product of 2 vect in sol2 (%o3) dot product of 2 vect in sol2(%o4) 0make trig substitution (%o6) [[1,-(sqrt(4*t^2+q^2-2*p*q+p^2)-q+p)/(2*t),0],[-1,-(sqrt(4*t^2+q^2-2*p*q+p^2)+q-p)/(2*t),0]](%o13) 0(%o14) [-6646.288740236717]
Ram