Question

If the complex number x = 3 + bi and |x|2 = 13, which is a possible value of b?

Answer 1

-2

Explanation:

x = 3 + bi, |x|2 = 13

⇒ |x|2 = 13

|x|2 = 32 + b2

13 = 9 + b2

13 - 9 = b2

b2 = 4

b = 2, -2