Answer:
A) W is a sub space of V
Step-by-step explanation:
given that [tex]V=R^4[/tex] and [tex]W= [(x_1,x_2,x_3,0)|x_1,x_2,x_3E..R] [/tex]
W is a subspace of V because of the follwing.
let [tex](x_1,x_2,x_3,0),(y_1,y_2,y_3,0)[/tex] ∈ [tex]W[/tex] and [tex]a,b[/tex] ∈ [tex]V [/tex]
now [tex]a(x_1,x_2,x_3,0)+b(y_1,y_2,y_3,0)= (ax_1, ax_2,ax_3,0)+(by_1, by_2,by_3, 0)\\\\=(ax_1, +by_1,ax_2+by_2,ax_3,+by_3,0+0)=(ax_1+by_1, ax_2+by_2,ax_3, +by_3,0)[/tex]∈ [tex]W[/tex]
since [tex]ax_1 +by_1,ax_2 ,+by_2,ax_3+by_3[/tex] are all elements of R
W is closed under vector adiition and scalar multiplication.
Hence W is a sub space of V.