What is the value of the product open paren 3 minus 2 i close paren times open paren 3 plus 2 i close paren ?
Answer
A
9 minus 4 i
B
9 plus 4 i
C
13
D
5
Explanation
The factors are conjugates, so use (a − b)(a + b) = a² − b². Here, (3 − 2i)(3 + 2i) = 3² − (2i)² = 9 − 4(−1) = 13, since i² = −1. The correct choice is 13.
AI-written and checked against the verified answer.