Aratati ca:
[tex]\left|\begin{array}{abc}1&a^{2} &a^{3} \\1&b^{2} &b^{3} \\1&c^{2} &c^{3} \end{array}\right|[/tex]=(b-a)(c-b)(c-a)(ab+bc+ca), unde a,b,c sunt nr reale