Download Algebra II Unit B: Radicals and Complex Numbers Section 4.6

August 30, 2013
Algebra II
Unit B: Radicals and Complex Numbers
Section 4.6 Perform Operations with Complex Numbers
Objectives
*Add, subtract, multiply & divide complex numbers
*Evaluate powers of i
Assignment: Worksheet 4-6
August 30, 2013
Complex Numbers
Standard form: a + bi or a - bi
Ex:
Ex: Adding and Subtracting Complex Numbers
(a + bi) + (c + di) = (a+c) + (b+d)i
a) (12 + 4i) + (3 + 2i)
b) (-3 + i) + (2 - 2i)
c) (-5 - i) + (-1 - i)
d) (12 + 4i) - (3 + 2i)
e) (-3 + i) - (2 - 2i)
f) (-5 - i) - (-1 - i)
August 30, 2013
Ex: Multiplying Complex Numbers
Remember how to F.O.I.L.
(x + 3)(x - 7)
a) 2i(3 + 4i)
b) -4(2 - 3i)
c) -3i(6 + 2i)
d) (3 + i)(5 + i)
e) (4 + i)(2 - 3i)
f) (-6 - 2i)(-3 - 4i)
g) (2 + 2i)
2
h) (7 - 4i)
2
August 30, 2013
Use properties of exponents to simplify. Write complex numbers in
standard form.
a) 2 + 4i
4
7
b) -4 - 6i
Now solve a quadratic equation with complex numbers.
2
a) 2x + 11 = -37
2
b) 2x + 18 = -72