7. Linear Algebra: Orthogonal ColumnsLet M be\begin{tabular}{|l|l|l|}\hline 1 & 3 & 1 \\\hline 2 & −2 & a \\\hline 1 & 1 & b \\\hline\end{tabular}and tet a and b be such that the columns of M are orthogonat. Compute aPick ONE option−1/2−11/22Ciear Selection
Q. 7. Linear Algebra: Orthogonal ColumnsLet M be\begin{tabular}{|l|l|l|}\hline 1 & 3 & 1 \\\hline 2 & −2 & a \\\hline 1 & 1 & b \\\hline\end{tabular}and tet a and b be such that the columns of M are orthogonat. Compute aPick ONE option−1/2−11/22Ciear Selection
Determine value of a: To determine the value of a, we need to ensure that the dot product of the first and second columns of matrix M is zero, since orthogonal columns have a dot product of zero.The first column of M is [1,2,1] and the second column is [3,−2,a].The dot product of these two columns is calculated as follows:(1×3)+(2×−2)+(1×a)=03−4+a=0a=1
Calculate dot product: Now, we need to check if the third column [1,b] is orthogonal to the other two columns. Since we only have a value for a and not for b, we can only check the orthogonality with respect to a. The dot product of the first and third columns is: (1×1)+(2×b)+(1×1)=01+2b+1=02b=−2b=−1
Check orthogonality: However, we made a mistake in the previous step. We were only asked to compute a, not b. Therefore, we should not have calculated the value of b. We will disregard the previous step's calculation for b and focus on the value of a that we found.