216 Solutions
t
/,
wis
,r w ^
0'
•**>*
A
.ttT*
R(A)=Span(yi.y 2 )
Fig. S.4. The range and null spaces of A — [j/i |y2J2/3]
where Vjv
-1
-e, S, =
-10 0
: '•• 0
_1 ... _i
0"
0_
) &II [l,...,l] = e
T.
Thus, 11(A) = Span {j/i, • • • , yn-i}- A/-(A) = Span {£}, where
* =
r-vwi
L
J
i J
i—i
i
Moreover,
1l(AT) = Span {-yn, -yi, ••• , -yn-2} •
And finally, Af(AT) = Span {5//} = Span {[1, • • • , 1]T} = Span {e}. We
have Af(A) = (ftM)-^1 - since A/"U) = -^(A- ) (therefore, 1Z(AT) = 11(A)
by the Fundamental Theorem of Linear Algebra-part 2) in this particular
exercise.