Definition:Wronskian/General Definition

Definition
Let $f_1 \left({x}\right), f_2 \left({x}\right), \ldots, f_n \left({x}\right)$ be real functions defined on a closed interval $\left[{a \,.\,.\, b}\right]$.

Let $f_1, f_2, \ldots, f_n$ be $n-1$ times differentiable on $\left[{a \,.\,.\, b}\right]$.

The Wronskian of $f_1, f_2, \ldots, f_n$ on $\left[{a \,.\,.\, b}\right]$ is defined as:


 * $W \left({f_1, f_2, \ldots, f_n}\right) = \begin{vmatrix}

f_1 \left({x}\right) & f_2 \left({x}\right) & \cdots & f_n \left({x}\right) \\ {f_1}' \left({x}\right) & {f_2}' \left({x}\right) & \cdots & {f_n}' \left({x}\right) \\ \vdots & \vdots & \ddots & \vdots \\ {f_1}^{\left({n - 1}\right)} \left({x}\right) & {f_2}^{\left({n - 1}\right)} \left({x}\right) & \cdots & {f_n}^{\left({n - 1}\right)} \left({x}\right) \\ \end{vmatrix}$

where:
 * $\begin{vmatrix} \cdots \end{vmatrix}$ denotes the determinant
 * ${f_1}^{\left({n - 1}\right)} \left({x}\right)$ denotes the $n-1$th derivative of $f_1$.