7.3 Complex Numbers: Trig Form Day 1
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7.3 Complex Numbers: Trig Form Day 1. Do Now Simplify (2 + i ) (3 – 2i) i^33. HW Review: p.198 #1-85. Graphing Complex Numbers. Complex numbers can be graphed just like real numbers The horizontal (x) axis is the real axis The vertical (y) axis is the imaginary axis. Ex.
7.3 Complex Numbers: Trig Form Day 1
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7.3 Complex Numbers: Trig FormDay 1 Do Now Simplify (2 + i) (3 – 2i) i^33
Graphing Complex Numbers • Complex numbers can be graphed just like real numbers • The horizontal (x) axis is the real axis • The vertical (y) axis is the imaginary axis
Ex • Graph each of the following • 1) 3 + 2i • 2) -4 – 5i • 3) -3i
Absolute Value of a Complex Number • The absolute value of a complex number a + bi is
Ex • Find the absolute value of each • 1) 3 + 4i • 2) -2 – i • 3) 4/5 i
Trigonometric Notation for Complex Numbers • Let’s consider the angle created by a complex number a + bi • This is trigonometric notation for a complex number
Trig Notation for Complex Numbers • r is the absolute value of a + bi • Theta is called the argument of a + bi • This notation is also known as polar notation
Ex • Find trigonometric notation for each of the following • 1) • 2)
Ex • Find standard notation, a + bi, for each of the following complex numbers • 1) • 2)
Closure • Write -5 + 5i in trigonometric notation • HW: p.632 #1-31 odds • 7.1-7.3 Quiz Thurs April 24
Complex Numbers: Trig FormDay 2 • Do Now • Find trigonometric notation for 2 + 3i
Complex Numbers: Multiplication • For any complex numbers
Ex • Multiply
Ex • Multiply
Ex • Convert to trigonometric notation and multiply
Complex Numbers: Division • For any complex numbers
Ex • Divide
Ex • Convert to trigonometric notation and divide
Closure • Multiply • HW: p.632 #33-43 odds
Complex Numbers: Trig FormDay 3 • Do Now • Convert to trig notation
DeMoivre’s Theorem • For any complex number and any natural number n,
Ex • Find each of the following • 1) • 2)
Roots of Complex Numbers • The nth roots of a complex number are given by • Where k = 0, 1, 2, …, n-1
Ex • Find the square roots of
Ex • Find the cube roots of 1
Closure • Evaluate in trigonometric notation • HW: p.633 #45-75 odds
7.1-7.3 ReviewDay 4 • Do Now • Find all complex solutions of the equation
7.1-7.3 Review • 7.1 Law of Sines • Solve triangles • Find area of triangles • 7.2 Law of Cosines • Solve triangles • 7.3 Complex Numbers in Trig Notation • Trig notation of complex numbers • Multiply, divide, powers, and roots
Closure • When do we use the Law of Sines versus the Law of Cosines to solve triangles? • What is trigonometric notation for complex numbers • 7.1-7.3 Quiz Tomorrow