Matrices & Determinants Question - None

Question

If A = \begin{pmatrix} 1 & 2 \ 2 & 1 \end{pmatrix} and f(x) = \frac{1+x}{1-x}, then f(A) is

Accepted Answer

Solution:

Given A = \begin{pmatrix} 1 & 2 \ 2 & 1 \end{pmatrix} and f(x) = \frac{1+x}{1-x}

We need to find f(A) = \frac{I + A}{I - A}

I + A = \begin{pmatrix} 2 & 2 \ 2 & 2 \end{pmatrix}

I - A = \begin{pmatrix} 0 & -2 \ -2 & 0 \end{pmatrix}

Therefore, f(A) = \begin{pmatrix} 1 & 1 \ 1 & 1 \end{pmatrix}

∴ Answer is (a)

Question: