Question : The sides of a triangle are 9 cm, 6 cm, and 5 cm. What is the value of the circumradius of this triangle?

Option 1: $\frac{9 \sqrt{2}}{2} \mathrm{~cm}$

Option 2: $\frac{9 \sqrt{3}}{5} \mathrm{~cm}$

Option 3: $\frac{9 \sqrt{3}}{4} \mathrm{~cm}$

Option 4: $\frac{27 \sqrt{2}}{8} \mathrm{~cm}$

Question : If $x=(\sqrt{6}-1)^{\frac{1}{3}}$, then the value of $\left(x-\frac{1}{x}\right)^3+3\left(x-\frac{1}{x}\right)$ is:

Option 1: $\frac{2 \sqrt{6}-6}{5}$

Option 2: $\frac{4 \sqrt{6}-6}{5}$

Option 3: $\frac{4 \sqrt{6}-6}{3}$

Option 4: $\frac{4 \sqrt{3}-6}{5}$

Question : If $\sqrt{\frac{\mathrm{a}}{\mathrm{b}}}=\frac{8}{3}-\sqrt{\frac{\mathrm{b}}{\mathrm{a}}}$ and $a-b=10$, then the value of $ab$ is:

Option 1: $32 \frac{1}{7}$

Option 2: $32 \frac{3}{7}$

Option 3: $32 \frac{4}{7}$

Option 4: $32 \frac{2}{7}$

Question : If $x=5–\sqrt{21}$, the value of $\frac{\sqrt{x}}{\sqrt{32–2x}–\sqrt{21}}$ is:

Option 1: $\frac{1}{\sqrt2}(\sqrt{3}–\sqrt{7})$

Option 2: $\frac{1}{\sqrt2}(\sqrt{7}–\sqrt{3})$

Option 3: $\frac{1}{\sqrt2}(\sqrt{7}+\sqrt{3})$

Option 4: $\frac{1}{\sqrt2}(7–\sqrt{3})$

Question : If $\sec A=\frac{9}{4}$, then what is the value of $\cot A$?

Option 1: $\frac{4}{\sqrt{65}}$

Option 2: $\frac{9}{\sqrt{65}}$

Option 3: $\frac{\sqrt{65}}{9}$

Option 4: $\frac{\sqrt{65}}{4}$