\(\frac{π}{3}\)
The correct option is(B): \(\frac{π}{3}\)
\(A=\begin{bmatrix}cosα& -sinα\\ sinα& cosα\end{bmatrix}\)
\(A'=\begin{bmatrix}cosα& sinα\\ -sinα& cosα\end{bmatrix}\)
Now A+A=I
\(\begin{bmatrix}cosα& -sinα\\ sinα& cosα\end{bmatrix}+\begin{bmatrix}cosα& sinα\\ -sinα& cosα\end{bmatrix}=\begin{bmatrix}1&0\\0&1\end{bmatrix}\)
\(=>\begin{bmatrix}2cosα& 0\\ 0& 2cosα\end{bmatrix}=\begin{bmatrix}1&0\\0&1\end{bmatrix}\)
Comparing the corresponding elements of the two matrices, we have:
2cosα=1
=>\(cos a=\frac{1}{2}=cos\frac{\pi}{3}\)
Therefore \(α=\frac{π}{3}\)
A matrix is a rectangular array of numbers, variables, symbols, or expressions that are defined for the operations like subtraction, addition, and multiplications. The size of a matrix is determined by the number of rows and columns in the matrix.