About Complex Numbers:

The imaginary unit is defined as the square root of -1. With this definition, we can discuss the idea of a complex number. A complex number is of the form a + bi, where a and b are real numbers and i represents the imaginary unit.


Test Objectives
  • Demonstrate the ability to simplify the square root of a negative number
  • Demonstrate the ability to multiply/divide square roots of negative numbers
  • Demonstrate the ability to perform operations with complex numbers
  • Demonstrate the ability to simplify powers of i
Complex Numbers Practice Test:

#1:

Instructions: Simplify each.

a) $$\sqrt{-45}$$

b) $$\sqrt{-125}$$

c) $$\sqrt{-147}$$


#2:

Instructions: Simplify each.

a) $$(-1 + 4i) - (2 + 3i) - (3 + i)$$

b) $$(-7 - 6i) + (-3 - 3i) - (-3 - 5i)$$


#3:

Instructions: Simplify each.

a) $$-3(8 + 5i)(2 + 3i)$$

b) $$(-7 + 7i)(6 + 4i)(1 - i)$$


#4:

Instructions: Simplify each.

a) $$\frac{5 + 3i}{1 + 2i}$$

b) $$\frac{10 + 5i}{-7 + 4i}$$


#5:

Instructions: Simplify each.

a) $$i^{103}$$

b) $$i^{58}$$

c) $$i^{260}$$

d) $$i^{72}$$


Written Solutions:

#1:

Solutions:

a) $$3i\sqrt{5}$$

b) $$5i\sqrt{5}$$

c) $$7i\sqrt{3}$$


#2:

Solutions:

a) $$-6$$

b) $$-7 - 4i$$


#3:

Solutions:

a) $$-3 - 102i$$

b) $$-56 + 84i$$


#4:

Solutions:

a) $$\frac{11}{5}- \frac{7}{5}i$$

b) $$-\frac{10}{13}- \frac{15}{13}i$$


#5:

Solutions:

a) $$-i$$

b) $$-1$$

c) $$1$$

d) $$1$$