10) A soma dos determinantes indlcados a seguir é a soma dos determinantes indicados a seguir é igual a zero \( \left|\begin{array}{cc}a & b \\ b & a\end{array}\right|+\left|\begin{array}{cc}-a & -b \\ b & a\end{array}\right| \) A) quaisquer que sejam os valores reais de a e de \( b \). B) se e somente se \( a=b \). C) se e somente se \( a=-b \). D) se e somente se \( a=0 \). E) se e somente se \( a=b=1 \).

(i)

Какое из приведенных неравенств будет линейным неравенством с одной переменной: \[ \begin{array}{l}\text { А) } x \geq 15 \\ \square \text { B) } x+4 \geq y \\ \square \text { C) } 5+9<27 \\ \square \text { D) } y>6,5 \\ \square \text { E) } 2 x>-2 \\ \square \text { F) } x y \leq \frac{3}{7}\end{array} \]

Use your calculator to evaluate \( \tan ^{-1}(0.67) \) to at least 3 decimal places

Add. \( \quad 15 \sqrt{-75}+9 \sqrt{-48} \)

10. The stress at which extension of a material takes place more quickly as compared to the increase in load, is called a) Elastic point b) Plastic point c) Breaking point d) Yielding point 11. Where in the stress-strain curve, the hooke's law is valid?