Wronskian

Definition

Wronskian of an ordered tuple of functions $f_1\dots f_n$ is defined as

$$W(f_1\dots f_n)=\left|\begin{array}{cccc}{f}_1& f_2& \dots & f_n\\ f^{(}{1)}_1& f_2^{(1)}& \dots & f_n^{(1)}\\ ⋮& ⋮& ⋮& ⋮\\ f_1^{(n-1)}& f_2^{(n-1)}& \dots & f_n^{(n-1)}\end{array}\right|$$