곡면 $z=x^2 + y^2 +4$, $x \geq 0$, $1 \leq x^2 + y^2 \leq 3$ 의 넓이는?

• ①$\displaystyle \frac{\pi} {12} \left (13 \sqrt 13 - 5 \sqrt 5 \right)$
• ②$\displaystyle \frac{\pi} {12} \left (17 \sqrt 17 - 13 \sqrt 13 \right)$
• ③$\displaystyle \frac{\pi} {6} \left (13 \sqrt 13 - 5 \sqrt 5 \right)$
• ④$\displaystyle \frac{\pi} {6} \left (17 \sqrt 17 - 13 \sqrt 13 \right)$
• ⑤$\displaystyle \frac{\pi} {6} \left (17 \sqrt 17 - 5 \sqrt 5 \right)$