Since the 16th century, similar formulas (using cube roots in addition to square roots), but much more complicated are known for equations of degree three and four (see cubic equation and quartic equation).
Daweg abad ke-16, rumus sané pateh (nganggén akar pangkat tiga tiosan ring akar kuadrat), nanging karasayang doh méwehan anggén persamaan derajat tiga miwah papat (cingak persamaan kubik miwah persamaan kuartik).