Complex Numbers
Sum of cross-conjugate products
MJAT_TS6_P2
Grade 12
Question:
**Paragraph I (continued):** $z_1\bar{z}_2+z_2\bar{z}_1+z_2\bar{z}_3+z_3\bar{z}_2+z_1\bar{z}_3+z_3\bar{z}_1=$
Step-by-Step Solution
Key Concept: $\sum_{i\neq j}z_i\bar{z}_j=|z_1+z_2+z_3|^2-(|z_1|^2+|z_2|^2+|z_3|^2)=441-(27+132)=282$.
$\mathbf{282}$.
Correct Answer: 282