Solve for x after x and d have been reassigned new values after e4 yields an error [].



Solve for x after x and d have been reassigned new values after e4 yields an
error [].

 

I have the following expressions.

 

(%i1) e1: x^2+d*y*4+d^2*(-4);

                                            2      2

(%o1)                          4 d y + x  - 4 d

(%i2) e2: solve(e1, y);

                                                2      2

                                              x  - 4 d

(%o2)                          [y = - ---------]

                                                 4 d

(%i3) e3: subst([y=0, d=5], e1);

                                          2

(%o3)                              x  - 100

(%i4) e4: solve(e3, x);

(%o4)                         [x = - 10, x = 10]

(%i5) e5: subst([x=50, d=25], e2);

(%o5)                               [y = 0]

 

Now e4 has been reassigned new values at e5, x=50 and d=50. If I write e6:
solve(e5,x); then I get [].

 

(%i6) e6: solve(e5,x);

(%o6)                                []

 

Can anyone help with this?

 

 

William Porter

wporter at omegapar.com