Question

If the modulus of the complex number a + bi equals a, then we KNOW that

Answer 1

b = 0

Explanation:

The modulus of a + bi is

| a + bi | =
`√(a^2+b^2)` , then

`√(a^2+b^2)` = a ( square both sides )

a² + b² = a² ( subtract a² from both sides )

b² = 0 ⇒ b = 0