Revision history [back]

Instead of "assigning" a value to $\partial g/\partial x \vert_{x=0}$ beforehand, it's easier to make the substitution afterward:

sage: der_f.subs(x==0).subs(diff(g,x).subs(x==0) == 10)
12

Instead of "assigning" a value to $\partial g/\partial x \vert_{x=0}$ beforehand, it's easier to make the substitution afterward:

sage: der_f.subs(x==0).subs(diff(g,x).subs(x==0) == 10)
12

sage: what_i_know = diff(g,x).subs(x==0) == 10
sage: der_f.subs(x==0).subs(what_i_know)
12