>>>>> "GA" == Grze? Andruszkiewicz <gandrusz at gmail.com> writes:
GA> sum((R[i]-(a*X[i]+b)*t + 1/2*(c*X[i]+d)^2*t)^2/((c*X[i]+d)^2*t), i, 1, N);
GA> diff(%, a);
I get:
:; rmaxima
Maxima 5.26.0 http://maxima.sourceforge.net
using Lisp SBCL 1.0.54
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) display2d:false;
(%o1) false
(%i2) sum((R[i]-(a*X[i]+b)*t + 1/2*(c*X[i]+d)^2*t)^2/((c*X[i]+d)^2*t), i, 1, N);
(%o2) ('sum(((c*X[i]+d)^2*t/2-(a*X[i]+b)*t+R[i])^2/(c*X[i]+d)^2,i,1,N))/t
(%i3) diff(%, a);
(%o3) -2*'sum(X[i]*((c*X[i]+d)^2*t/2-(a*X[i]+b)*t+R[i])/(c*X[i]+d)^2,i,1,N)
(%i4)
-JimC
--
James Cloos <cloos at jhcloos.com> OpenPGP: 1024D/ED7DAEA6