Given N-1 independent (not necessarily linear) equations in N variables, how do I tell Maple to find solutions in terms of a specific variable? For example: with(RealDomain); eq1:=x-1=a*cos(theta); eq2:=x+1=a*sin(theta); I want to find a and theta in terms of x: a=sqrt(2*x^2+2), theta=arctan((x+1)/(x-1)) solve({eq1,eq2},[a,theta]) appears to give me solutions based on elimination of x.