Consider T:R² → R² be the linear operator given by the formula T(x,y)=(x+ky,-y).
Show that T is one-one for every real value of k and that T^{-1}=T.
Here, the liner operator T(x,y)=(x+ky,-y) is given.
The standard matrix for this operator is T=\left[{\begin{array}{c c}{1}&{k}\\ {0}&{-1}\end{array}}\right]\!\!.
By Theorem 3.1, Ker(T)={0}, because |T|=−1≠0 for any value of k . T(X)=0 has a unique solution.
Therefore, T is the one-one transformation for any value of k .
T^{-1}={\frac{\mathrm{adj}T}{|T|}}={\frac{1}{-1}}{\left[\begin{array}{c c}{-1}&{-k}\\ {0}&{1}\end{array}\right]} \\ \qquad \ \ =\left[{\begin{array}{c c}{1}&{k}\\ {0}&{-1}\end{array}}\right] \\ \qquad =T.Hence, the proof.