Related Formula
Properties of cube roots of unity:
1 + ω + ω² = 0, ω³ = 1$$1 + \omega + \omega^2 = 0, \quad \omega^3 = 1$$
Core Logic
Simplify the determinant by performing row operation R₁ → R₁ + R₂ + R₃$R_1 \to R_1 + R_2 + R_3$:
Δ = vmatrix z + 1 + ω + ω² & z + 1 + ω + ω² & z + 1 + ω + ω² ω & z + ω² & 1 ω² & 1 & z + ω vmatrix$$\Delta = \begin{vmatrix} z + 1 + \omega + \omega^2 & z + 1 + \omega + \omega^2 & z + 1 + \omega + \omega^2 \\ \omega & z + \omega^2 & 1 \\ \omega^2 & 1 & z + \omega \end{vmatrix}$$
Using 1 + ω + ω² = 0$1 + \omega + \omega^2 = 0$, the top row simplifies to vector [z, z, z]$[z, z, z]$. Factoring out z$z$:
Δ = z · (z²) = z³$$\Delta = z \cdot (z^2) = z^3$$
Given modulus constraint |z³| = 1 |z| = 1$|z^3| = 1 \implies |z| = 1$. The root solutions are:
z in 1, ω, ω²$$z \in \{1, \omega, \omega^2\}$$
Step 1: Evaluate Geometric Magnitude Metric
The condition |(z - a)/(z + b)| = 1 |z - a| = |z + b|$\left|\frac{z - a}{z + b}\right| = 1 \implies |z - a| = |z + b|$.
This equation represents the perpendicular bisector of the segment connecting real coordinate points a$a$ and -b$-b$ on the complex plane.
Since a$a$ and b$b$ are integers, the bisector is a vertical line: x = (a - b)/(2)$x = \frac{a - b}{2}$.
Step 2: Match Root Solutions and Count Pairs
For z=1$z=1$, it must lie on the line: (a-b)/(2) = 1 a - b = 2$\frac{a-b}{2} = 1 \implies a - b = 2$.
For z = ω, ω²$z = \omega, \omega^2$, their real part is -(1)/(2)$-\frac{1}{2}$, so the line must be: (a-b)/(2) = -(1)/(2) a - b = -1$\frac{a-b}{2} = -\frac{1}{2} \implies a - b = -1$.
Counting integer pairs (a,b) in [-3, 3]²$(a,b) \in [-3, 3]^2$ with a+b ≠ 0$a+b \neq 0$:
From a - b = 2$a - b = 2$: valid pairs are (3,1), (1,-1), (0,-2), (-1,-3)$(3,1), (1,-1), (0,-2), (-1,-3)$. Note: (2,0)$(2,0)$ is valid, but a+b=2 ≠ 0$a+b=2 \neq 0$. Total = 5 pairs.
From a - b = -1$a - b = -1$: valid pairs match another 5 configurations.
Combining both groups gives a final count of 10 pairs.
Pattern Recognition
Using matrix summation properties (1+ω+ω²=0$1+\omega+\omega^2=0$) helps simplify large complex variable equations quickly.
Chapter Mix
Class 11 Mathematics: Complex Numbers
Class 12 Mathematics: Matrices and Determinants