L=
\left[\begin{matrix}2 & 0& 0 \1 & -2& 0\a & 1 & 3\end{matrix} ight]

and
U =
\left[\begin{matrix}1 & 4& b \0 & -1& 5\0 & 0 & c\end{matrix} ight]

(i) Determine all the value of a so that the (3,2) entry of LU is 7.

(ii) Determine all values of b and c so thtat the (2,3) entry of LU is 0.

Question

L= 
\left[\begin{matrix}2 & 0& 0 \1 & -2& 0\a  & 1 & 3\end{matrix}ight]

and
U = 
\left[\begin{matrix}1 & 4& b \0 & -1& 5\0  & 0 & c\end{matrix}ight]



(i) Determine all the value of a so that the (3,2) entry of LU is 7. 

(ii) Determine all values of b and c so thtat the (2,3) entry of LU is 0.

anonymous · Answer

i found a = 2 and b =10. How to find c?

anonymous · Answer

c can be anything, since: 1xb-2x5 + 0xc = 0 only depends on b