Suppose V is vector space and S,T ∈ L(V,V) are such that range(S) ⊂ ker(T).
Prove (ST)(ST) = 0
Now, I know that this means that if you apply the linear transformation S to any v in V, then you get S(v) = 0. Apart from that, I am a little stuck as to how I should solve this problem... Any help would be appreciated!