Let A= pmatrix 2 & 1 1 & 1 pmatrix , B= pmatrix 1 & -1 -1 & p pmatrix with

MATHEMATICS · Subjective · AP · AP Precalculus · Functions with Parameters, Vectors, and Matrices · Functions with Parameters, Vectors, and Matrices

Problem

Let

A=\begin{pmatrix}2 & 1\\ 1 & 1\end{pmatrix},\quad B=\begin{pmatrix}1 & -1\\ -1 & p\end{pmatrix}

with

AB=I_2

. Find the value of

p