I am aware that for expressions in the type eq=c0+c1x+c2x2... the coefficients of x can be expressed as decimals by doing eq.polinomial(RR) however, I noticed that if it is in the form eq=c0+c1xc2+c3x or in any form where it is impossible to express as c0+c1xn where n is some power of x, the eq.polinomial(RR) only returns an error giving TypeError: fraction must have unit denominator. How can I approximate eq=c0+c1xc2+c3x where c_0, c_1, c_2, c_3 are some decimals? I am aware that c0+c1xc2+c3x however I do not know what it is.