170 likes | 179 Views
Explore the world of complex numbers - imaginary and pure imaginary numbers, operations, properties, equations, and applications in electric circuits. Learn to simplify, add, subtract, multiply, and divide complex numbers.
E N D
New kinds of numbers • In previous classes, you have heard “all real numbers” What are unreal numbers? • The “imaginary Unit” i is defined to be i2 = -1 • Or i = • Numbers such as 6i, -4i, or iare called pure imaginary numbers. They represent square roots of negative numbers. Ie = ·2i
Simplify Radicals A. B.
Equations with Pure Imaginary Solutions • Solve 5y2 + 20 = 0.
Operations with Pure Imaginary Numbers B. • A.Simplify –3i ● 2i.
Properties with Imaginary Numbers • Commutative Property : a + b = b + a • Associative Property : a + (b + c) = (a + b) + c • Powers of i
Equate Complex Numbers • Find the values of x and y that make the equation 2x + yi = –14 – 3i true.
Operations with complex Numbers: Add/Subtract • Combine Real parts, combine imaginary parts • A.Simplify (3 + 5i) + (2 – 4i). B.Simplify (4 – 6i) – (3 – 7i).
Operations with complex Numbers: Multiply • Multiply using distributive property (FOIL) • (5 + 2i)(4 – 6i) • (8 – 3i)2
Conjugates • a + bi and a – bi • When you multiply conjugates together all imaginary numbers go away.
Conjugates • Find the product of (8 + 2i) and (8 – 2i) • Find the product of (3 – 5i) and (3 + 5i)
Writing Equations • Write a quadratic equation in standard form with 5i and -5i as solutions. • Write a quadratic equation in standard form with 3+i and 3 – i
Application • ELECTRICITYIn an AC circuit, the voltage E, current I, and impedance Z are related by the formula E = I ● Z. Find the voltage in a circuit with current 1 + 4j amps and impedance 3 – 6j ohms.
Find the values of x and y that make the equation 3x – yi = 15 + 2i true. A.x = 15y = 2 B.x = 5y = 2 C.x = 15y = –2 D.x = 5y = –2