Root-finding algorithm cubic polynomial may involve non-real cube roots). For polynomials of degree five or higher Abel–Ruffini theorem asserts that there is, in general, no radical expression of the roots. So, except for very low degrees, root finding of polynomials consists of finding approximations of the roots. By the fundamental theorem of algebra, one knows that a polynomial of degree has at most real or complex roots, and the this number is reached for almost all polynomials. It follows that the problem of root finding for polynomials may be split in three different subproblems; For finding one root, Newton's method and other
Cube root be −2, , or . This is related with the concept of monodromy: if one follows by continuity the function "cube root" along a closed path around zero, after a turn the value of the cube root is multiplied (or divided) by formula_10 Cube roots arise in the problem of finding an angle whose measure is one third that of a given angle (angle trisection) and in the problem of finding the edge of a cube whose volume is twice that of a cube with a given edge (doubling the cube). In 1837 Pierre Wantzel proved that neither of these