ans

40605
$6$

40606
$90$

40607
$10$

40608
$15$

40609
$24$

40610
$(0,\dfrac{9\sqrt{2}-2}4]$

40611
$540$

40612
$\dfrac{16\pi}3$

40613
$35$

40614
\textcircled{2}\textcircled{4}

40615
$[6,+\infty)$

40616
$\log_2 \mathrm{e}$

40617
C

40618
A

40619
D

40620
B

40621
(1) $\dfrac{\sqrt{10}}{10}$; (2) $\dfrac{3\sqrt{5}}{5}$

40622
(1) $80$; (2) $1$或$-3$

40623
(1) $\pm \sqrt{3}$; (2) 存在, 点$M$的坐标为$(-3,0)$

40624
(1) $\dfrac{x^2}4+y^2=1$; (2) $k=\pm 2$; (3) 定值为$\dfrac 23$, 证明略

40625
(1) $y=-2$; (2) $k=0$或$4$; (3) $\dfrac 34-\ln 2$