Suppose V1,V2,VM is linearly independent in V and W€V.Prove that dim span(V1+W1,V2+W,.....VM+W)> or equal to m-1.
2.Suppose U1,U2,.....Um are finite dimensional subspaces of V.Prove that U1+U2+.....Um is finite dimensional and dim(U1+U2+.....Um)<or equal to dim U1+dim U2+.......dim Um.
1.Let { } is linearly independent in V and
Suppose is Linearly dependent. Then there esists scalars , not all zero such that
Rearranging the equation-
If were zero, then the equation above would contradict the linear independence of { }. Thus
Thus divide both sides of the equation by showing that
2.Suppose are finite-dimensional subspaces of V.
Thus, Each has a finite basis.
Concatenate these lists to get a spanning list of length
This shows that is finite dimensional and since any spanning list can be reduced
to a basis then
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