What is wrong?



Try,

(%i1) eq10: w1-w2=-a*(p-d-m)^2 + a*(p-m)^2;
                                                                                                                             2                2
(out1)                                                                                                    w1 - w2 = a (p - m)  - a (p - m - d)
(%i2) eq11: w3-w1=-s*(p+d-m)^2 + s*(p-m)^2;
                                                                                                                           2                2
(out2)                                                                                                    w3 - w1 = (p - m)  s - (p - m + d)  s
(%i3) first(linsolve(eq10, a));
                                                                                                                            w2 - w1
(out3)                                                                                                           a = - ------------------
                                                                                                                                        2
                                                                                                                       2 d p - 2 d m - d
(%i4) subst(out3,eq10);
                                                                                                                       2                    2
                                                                                                            (p - m - d)  (w2 - w1)   (p - m)  (w2 - w1)
(out4)                                                                                            w1 - w2 = ---------------------- - ------------------
                                                                                                                               2                      2
                                                                                                              2 d p - 2 d m - d      2 d p - 2 d m - d
(%i5) first(linsolve(eq11, s));
                                                                                                                            w3 - w1
(out5)                                                                                                           s = - ------------------
                                                                                                                                        2
                                                                                                                       2 d p - 2 d m + d
(%i6) subst(out5,eq11);
                                                                                                                       2                    2
                                                                                                            (p - m + d)  (w3 - w1)   (p - m)  (w3 - w1)
(out6)                                                                                   w3 - w1 = ----------------------  - ------------------
                                                                                                                               2                      2
                                                                                                              2 d p - 2 d m + d      2 d p - 2 d m + d
(%i7)

Rich



From: Mein Linuxrechner Arbeit 
Sent: Tuesday, July 13, 2010 4:33 AM
To: maxima at math.utexas.edu 
Subject: What is wrong?


Hello,

I tried to replase a in eq11 by the expression on the right side of "=".  [a=-(w2-w1)/(2*d*p-2*d*m-d^2)]
Bit instead of doing that, s is simply replaced by a.
How can I make maxima do what I want?


Thanks in advance




(%i1) eq10: w1-w2=-a*(p-d-m)^2 + a*(p-m)^2; 


(%i2) eq11: w3-w1=-s*(p+d-m)^2 + s*(p-m)^2; 


(%i3) linsolve(eq10,[a]); 


(%i4) eq11: subst(a,s,eq11); 




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