1.
Let ? be a finite dimensional vector space with basis {?1,...,??}
and ? ∈ L(?).
Show the following are equivalent:
(a) The matrix for ? is upper triangular. (b) ?(??) ∈
Span(?1,...,??) for all ?.
(c) Span(?1,...,??) is ?-invariant for all ?.
please also explain for (a)->(b) why are all the c
coefficients 0 for all i>k? and why T(vk) in the span of
(v1,.....,vk)? i need help understanding this.