let $V$ be a vector space from dimantion $n$ and $V^{\star}$ be a map from $V$ to $R$ ($V^{\star}$: $V$$\mapsto$$R$) and $A$ be a matrix from a bilineare form $T$:$V$$\times$V$^{\star}$ $\mapsto$$R$ with respect to the standaard basis $e_1$...$e_n$ from $V$ and his dual basis $e_1^{\star}$...$e_n^{\star}$.
how changes matrix $A$ if we $T$ with respect to another set of dual basis $f_1$...$f_n$,$f_1^{\star}$...$f_n^{\star}$ represent ?