I have a vector space A, with B and C are the two subspaces of A.
I need to disprove that dim(B+C)=dim(B)+dim(C)
I know the correct formula should be dim(B+C)=dim(B)+dim(C) - dim(B intersect C)
need to find a counterexample, but am struggling.
I have a vector space A, with B and C are the two subspaces of A.
I need to disprove that dim(B+C)=dim(B)+dim(C)
I know the correct formula should be dim(B+C)=dim(B)+dim(C) - dim(B intersect C)
need to find a counterexample, but am struggling.