> I want to know how to let Maxima know a relationship, bx^2+by^^2+bz^2==1, when simplifying formula.
Maybe ratsubst does what you need:
(%i25) ratsubst(1,bx^2+by^2+bz^2,C.S);
(%o25) matrix([-bz,-(by*bz)/bx,-(bz^2-1)/bx],[by/bx,-1,0])
I'm guessing you meant bx^2+by^2+bz^2 = 1, not bx^2+by^^2+bz^2 = 1; see
(%i28) ? ^^;
-- Operator: ^^
Noncommutative exponentiation operator. `^^' is the
exponentiation operator corresponding to noncommutative
multiplication `.', ....
--Barton
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