7. cvičení

$$ \xdef\mcal#1{\mathcal{#1}} \xdef\scal#1#2{\langle #1, #2 \rangle} \xdef\N{\mathbb N} \xdef\R{\mathbb R} \xdef\Q{\mathbb{Q}} \xdef\Z{\mathbb{Z}} \xdef\D{\mathbb{D}} \xdef\bm#1{\boldsymbol{#1}} \xdef\vv#1{\mathbf{#1}} \xdef\vvp#1{\pmb{#1}} \xdef\floor#1{\lfloor #1 \rfloor} \xdef\ceil#1{\lceil #1 \rceil} \xdef\grad#1{\mathrm{grad} , #1} \xdef\ve{\varepsilon} \xdef\im#1{\mathrm{im}(#1)} \xdef\tr#1{\mathrm{tr}(#1)} \xdef\norm#1{\left\vert \left\vert #1 \right\vert\right\vert} \xdef\scal#1#2{\langle #1, #2 \rangle} \xdef\ex#1{\mathrm{E} ,\left( #1\right)} \xdef\exv#1{\mathrm{E}, \vv{#1}} $$