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    IB Math AASL
    /
    Sequences & Series
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    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.

    Sequences & Series

    Video Reviews

    Watch comprehensive video reviews for Sequences & Series, 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.

    SequencesSeriesPaper 1 ProblemsFinancePaper 2 Problems

    The video will automatically pause when it reaches a problem.

    Infinite Geometric Series

    SL AA 1.8

    If a geometric sequence has a common ratio ∣r∣<1, then each term will be smaller than the previous term. As the terms get smaller and smaller, the sum of all the terms actually approaches a finite value:


    S∞​=1−ru1​​,∣r∣<1📖


    Powered by Desmos


    Example:

    Find the sum of all the terms in the infinite geometric sequence with u1​=4 and r=21​.


    S∞​=1−21​4​=21​4​=8

    Infinite Geometric Series

    SL AA 1.8

    If a geometric sequence has a common ratio ∣r∣<1, then each term will be smaller than the previous term. As the terms get smaller and smaller, the sum of all the terms actually approaches a finite value:


    S∞​=1−ru1​​,∣r∣<1📖


    Powered by Desmos


    Example:

    Find the sum of all the terms in the infinite geometric sequence with u1​=4 and r=21​.


    S∞​=1−21​4​=21​4​=8
    SequencesSeriesPaper 1 ProblemsFinancePaper 2 Problems