SAT · Mathematics · Complex Numbers — T/F

Exercise and reference answers

Questions

1. Statement is true

   Yes

   Statement

   i² = −1.

2. Statement is true

   Yes

   Statement

   i⁴ = 1.

3. Statement is true

   Yes

   Statement

   (2 + 3i) + (1 − 2i) = 3 + i.

4. Statement is true

   No

   Statement

   (2 + 3i)(1 − 2i) = 2 − 6i² = 8 + (−1)i.

5. Statement is true

   Yes

   Statement

   The complex conjugate of (a + bi) is (a − bi).

6. Statement is true

   Yes

   Statement

   |3 + 4i| = 5.

Instructions

Decide each statement about complex numbers.