$\displaystyle \int _ {V} (\sin 2 x \times \cos 2 y) d V$ 의 값은?

(이 때, $\displaystyle 0 \leq x \leq \frac{\pi} {4}, \frac{\pi} {4} -x \leq y \leq \frac{\pi} {4}$, $0 \leq z \leq 6, d V=d x d y d z)$

• ①$\displaystyle \frac{1} {2}$
• ②$\displaystyle \frac{2} {3}$
• ③$\displaystyle \frac{3} {4}$
• ④$1$