grandes-ecoles 2023 Q17

grandes-ecoles · France · x-ens-maths-a__mp Proof Existence Proof

Using the above, show that there exists a basis $(e_1, e_2)$ of $\mathbb{R}^2$ such that $\|Ax\| = \|x\|_2$ for $x \in \{e_1, e_2\}$.

Using the above, show that there exists a basis $(e_1, e_2)$ of $\mathbb{R}^2$ such that $\|Ax\| = \|x\|_2$ for $x \in \{e_1, e_2\}$.