no goals
R : Type u_1
S : Type ?u.287176
F : Type ?u.287179
K : Type ?u.287182
P Q : Cubic R
a b c d a' b' c' d' : R
inst✝ : Semiring R
h : toPoly P = toPoly Q
⊢ P.d = Q.d
rw [← coeff_eq_d, h, coeff_eq_d]