Let V {\displaystyle {}V} be a finite-dimensional K {\displaystyle {}K} -vector space, and let φ , ψ : V → V {\displaystyle {}\varphi ,\psi \colon V\rightarrow V} denote linear mappings. Show det ( φ ∘ ψ ) = det φ det ψ {\displaystyle {}\det {\left(\varphi \circ \psi \right)}=\det \varphi \det \psi } .
