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How to Calculate with Complex Numbers
Formula
Complex numbers have the form a + bi where i = sqrt(-1). Addition adds corresponding parts.
Multiplication uses FOIL: (a+bi)(c+di) = (ac-bd) + (ad+bc)i.
Common use cases:
- Electrical engineering AC circuit analysis
- Quantum mechanics wave functions
- Signal processing and Fourier transforms
Frequently Asked Questions
Sarah Chen
Financial Analyst, CFA
Sarah is a Chartered Financial Analyst with over 8 years of experience in investment management and financial modeling. She specializes in retirement planning and compound interest calculations.
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