Khan Academy on a Stick
Imaginary and complex numbers
Understanding and solving equations with imaginary numbers.
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Introduction to i and Imaginary Numbers
ccIntroduction to i and imaginary numbers
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Calculating i Raised to Arbitrary Exponents
ccCalculating i raised to arbitrarily high exponents
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Imaginary Roots of Negative Numbers
ccImaginary Roots of Negative Numbers
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i as the Principal Root of -1 (a little technical)
cci as the principal square root of -1
The imaginary unit i
This is where math starts to get really cool. It may seem strange to define a number whose square is negative one. Why do we do this? Because it fits a nice niche in the math ecosystem and can be used to solve problems in engineering and science (not to mention some of the coolest fractals are based on imaginary and complex numbers). The more you think about it, you might realize that all numbers, not just i, are very abstract.
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Complex numbers
ccComplex Numbers
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Complex numbers (part 1)
ccIntroduction to complex numbers. Adding, subtracting and multiplying complex numbers.
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Complex numbers (part 2)
ccDividing complex numbers. Complex conjugates.
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Adding Complex Numbers
ccAdding Complex Numbers
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Subtracting Complex Numbers
ccSubtracting Complex Numbers
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Multiplying Complex Numbers
ccMultiplying Complex Numbers
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Dividing Complex Numbers
ccDividing Complex Numbers
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Complex Conjugates Example
ccComplex Conjugates
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Example: Complex roots for a quadratic
ccComplex Roots from the Quadratic Formula
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Algebra II: Imaginary and Complex Numbers
cc23-26, mostly imaginary and complex numbers
Complex numbers
Let's start constructing numbers that have both a real and imaginary part. We'll call them complex. We can even plot them on the complex plane and use them to find the roots of ANY quadratic equation. The fun must not stop!