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    IB Math AAHL
    /
    Complex Numbers
    /

    Video

    Video Reviews

    Watch comprehensive video reviews for most units, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.

    Not your average video:

    Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.

    Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.

    Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.

    Not your average video:

    Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.

    Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.

    Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.

    Complex Numbers

    Video Reviews

    Watch comprehensive video reviews for Complex Numbers, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.

    Not your average video:

    Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.

    Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.

    Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.

    Not your average video:

    Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.

    Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.

    Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.

    Cartesian formPolar formDe Moivre

    The video will automatically pause when it reaches a problem.

    Complex Argument when a=0 (purely imaginary)

    AHL HL 1.12

    If a=0, then tan(argz)=ab​ is undefined. But we recall that tanθ is undefined for θ=2π​,23π​… So when a=0 we have

    arg(bi)=⎩⎪⎪⎪⎨⎪⎪⎪⎧​2π​b>0 23π​b<0​🚫


    This can be seen on the complex diagram by remembering that bi lies on the yi axis:


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    Example

    Find the argument of z=−3i.


    We have z=0−3i, so z is purely imaginary and lies along the y-axis. Since −3<0, the argument of z is argz=23π​.

    Complex Argument when a=0 (purely imaginary)

    AHL HL 1.12

    If a=0, then tan(argz)=ab​ is undefined. But we recall that tanθ is undefined for θ=2π​,23π​… So when a=0 we have

    arg(bi)=⎩⎪⎪⎪⎨⎪⎪⎪⎧​2π​b>0 23π​b<0​🚫


    This can be seen on the complex diagram by remembering that bi lies on the yi axis:


    Powered by Desmos

    Example

    Find the argument of z=−3i.


    We have z=0−3i, so z is purely imaginary and lies along the y-axis. Since −3<0, the argument of z is argz=23π​.

    Cartesian formPolar formDe Moivre