λ ( v ⋅ e ) = ( A v ) ⋅ e = ( A v ) T e = v T A T e = v T e = v ⋅ e ( λ − 1 ) ( v ⋅ e ) = 0 λ ≠ 1 v ⋅ e = 0 {\displaystyle {\begin{aligned}\lambda (v\cdot e)&=(Av)\cdot e\\&=(Av)^{T}e\\&=v^{T}A^{T}e\\&=v^{T}e\\&=v\cdot e\\(\lambda -1)(v\cdot e)&=0\\\lambda &\neq 1\\v\cdot e&=0\end{aligned}}}
