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    IB Math AAHL
    /
    Trig equations & identities
    /

    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.

    Trig equations & identities

    Video Reviews

    Watch comprehensive video reviews for Trig equations & identities, 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.

    Unit circleTrig functionsTrig equationsIdentitiesHL functionsHL Identities

    The video will automatically pause when it reaches a problem.

    Sine and cosine compound angle identities

    AHL 3.10

    The compound angle identities for sin and cos state that

    sin(A±B) cos(A±B)​=sinAcosB±cosAsinB📖 =cosAcosB∓sinAsinB📖​


    Example

    Find cos(12π​).


    Notice that 12π​=3π​−4π​, then

    cos(3π​−4π​)    ​=cos3π​⋅cos4π​+sin3π​sin4π​ =21​⋅2√2​+2√3​⋅2√2​ =4√2+√6​​

    Sine and cosine compound angle identities

    AHL 3.10

    The compound angle identities for sin and cos state that

    sin(A±B) cos(A±B)​=sinAcosB±cosAsinB📖 =cosAcosB∓sinAsinB📖​


    Example

    Find cos(12π​).


    Notice that 12π​=3π​−4π​, then

    cos(3π​−4π​)    ​=cos3π​⋅cos4π​+sin3π​sin4π​ =21​⋅2√2​+2√3​⋅2√2​ =4√2+√6​​
    Unit circleTrig functionsTrig equationsIdentitiesHL functionsHL Identities