v.a.: $x=0$ and h.a.: $y=4$
${\text{D}}_f=⟨\leftarrow ,0⟩\cup ⟨0,\to ⟩$
${\text{B}}_f=⟨\leftarrow ,4⟩\cup ⟨4,\to ⟩$

v.a.: $x=0$ and h.a.: $y=-1$
${\text{D}}_g=⟨\leftarrow ,0⟩\cup ⟨0,\to ⟩$
${\text{B}}_g=⟨\leftarrow ,-1⟩\cup ⟨-1,\to ⟩$

v.a.: $x=-2$ and $x=2$ en h.a.: $y=0$
${\text{D}}_h=⟨\leftarrow ,-2⟩\cup ⟨-2,2⟩\cup ⟨2,\to ⟩$
${\text{B}}_h=ℝ$

v.a.: none, and h.a.: $y=1$
${\text{D}}_k=ℝ$
${\text{B}}_k=⟨\leftarrow ,1⟩\cup ⟨1,\to ⟩$

the range is $[0.011;22]$

High pitch, wavelength $0.00275$ m

low (bass) sounds, wavelength longer than $16.5$ m

$W$ approaches $0$ m.

$(0,0)$

v.a.: $x=20$ and h.a.: $y=10$

$-200\le x\le 200$ and $0\le y\le 50$

$[0,\to \rangle$

$12.83$

$\mathrm{av}IC=\frac{\mathrm{TC}}{q}$
$\mathrm{av}IC=\frac{100}{q}+0.1q$

v.a.: $q=0$

The range is $[6.32;\to ⟩$