1.Suppose column 1+column 3+column 5=0 and
column 2-column 4=0 in a 4 by 5 matrix with three pivots.
Which columns are sure to have no pivots? What is the null space?
這裡我只有想到
[1 0 1 0 1] 矩陣會長這個樣子再來就不知道怎麼推了QQ
[0 1 0 -1 0]
[? ? ? ? ?]
[? ? ? ? ?]
2.Suppose you know that the 3 by 4 matrix has the vector
s1=(-2,1,0,0) and s2=(-2,0,-1,1) as the only two special solutions
T
to Ax=0. What is the exact rref R of A? What is the column space of A ?
這裡我推到的R=[1 2 0 2] 不曉得對不對
[0 0 0 0]
[0 0 1 1]
T T
CS(A ) =CS(R )=RS(R) 可是課本提到CS(A)=/=CS(R)
那這樣該怎麼作呢?
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