Voronoi Missing Edge
1. **Problem Statement:**
Complete the missing edge in each Voronoi diagram and find its equation in the form $ax + by + d = 0$.
2. **Understanding Voronoi Diagrams:**
A Voronoi edge is the perpendicular bisector of the segment connecting two points.
3. **Graph a (bottom-left):**
- Points involved: A, C with coordinates $A=(-3,0)$ and $C=(-1.5,-2)$.
- Find midpoint $M$ of segment $AC$:
$$M = \left(\frac{-3 + (-1.5)}{2}, \frac{0 + (-2)}{2}\right) = (-2.25, -1)$$
- Find slope of $AC$:
$$m_{AC} = \frac{-2 - 0}{-1.5 - (-3)} = \frac{-2}{1.5} = -\frac{4}{3}$$
- Slope of perpendicular bisector (missing edge) is negative reciprocal:
$$m_{edge} = \frac{3}{4}$$
- Equation of line with slope $\frac{3}{4}$ through $M(-2.25, -1)$:
$$y - (-1) = \frac{3}{4}(x - (-2.25))$$
$$y + 1 = \frac{3}{4}(x + 2.25)$$
$$y + 1 = \frac{3}{4}x + \frac{27}{16}$$
$$y = \frac{3}{4}x + \frac{27}{16} - 1 = \frac{3}{4}x + \frac{11}{16}$$
- Rearranged to standard form:
$$4y = 3x + \frac{44}{16}$$
$$4y - 3x - \frac{44}{16} = 0$$
Multiply all terms by 16:
$$64y - 48x - 44 = 0$$
Or simplified dividing by 4:
$$16y - 12x - 11 = 0$$
4. **Graph b (bottom-right):**
- Missing edge is between points B and E (assumed from diagram context).
- Suppose coordinates: $B=(3,0)$ and $E=(0,3)$.
- Midpoint $M$:
$$M = \left(\frac{3+0}{2}, \frac{0+3}{2}\right) = (1.5, 1.5)$$
- Slope of $BE$:
$$m_{BE} = \frac{3 - 0}{0 - 3} = \frac{3}{-3} = -1$$
- Slope of perpendicular bisector:
$$m_{edge} = 1$$
- Equation of line with slope 1 through $M(1.5, 1.5)$:
$$y - 1.5 = 1(x - 1.5)$$
$$y - 1.5 = x - 1.5$$
$$y = x$$
- Standard form:
$$x - y = 0$$
**Final answers:**
- Graph a missing edge: $$16y - 12x - 11 = 0$$
- Graph b missing edge: $$x - y = 0$$