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    IB Math AASL
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    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.

    Properties of Σ

    SL Core 1.2

    Sums with  ∑ ​ have the following properties:

    Sum of a sum:

    k=1∑n​(ak​+bk​)=k=1∑n​ak​+k=1∑n​bk​🚫


    Sum of a multiple:

    k=1∑n​cak​=ck=1∑n​ak​🚫


    Sum of constant:

    k=1∑n​c=c+c+⋯+c=n⋅c🚫


    Splitting the sum:

    k=1∑n​ak​=k=1∑m​ak​+k=m+1∑n​ak​🚫


    Example

    It is given that k=1∑11​ak​=40, k=1∑7​ak​=22, and k=8∑11​bk​=5.


    Find k=8∑11​(ak​+2bk​):

    k=8∑11​(ak​+2bk​)      ​=k=8∑11​ak​+2k=8∑11​bk​ =k=8∑11​ak​+2⋅5 =k=1∑11​ak​−k=1∑7​ak​+10 =40−22+10=28​

    Properties of Σ

    SL Core 1.2

    Sums with  ∑ ​ have the following properties:

    Sum of a sum:

    k=1∑n​(ak​+bk​)=k=1∑n​ak​+k=1∑n​bk​🚫


    Sum of a multiple:

    k=1∑n​cak​=ck=1∑n​ak​🚫


    Sum of constant:

    k=1∑n​c=c+c+⋯+c=n⋅c🚫


    Splitting the sum:

    k=1∑n​ak​=k=1∑m​ak​+k=m+1∑n​ak​🚫


    Example

    It is given that k=1∑11​ak​=40, k=1∑7​ak​=22, and k=8∑11​bk​=5.


    Find k=8∑11​(ak​+2bk​):

    k=8∑11​(ak​+2bk​)      ​=k=8∑11​ak​+2k=8∑11​bk​ =k=8∑11​ak​+2⋅5 =k=1∑11​ak​−k=1∑7​ak​+10 =40−22+10=28​
    SequencesSeriesPaper 1 ProblemsFinancePaper 2 Problems