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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.

    Tan double angle identity

    AHL 3.10

    The double angle identity for tan states that

    tan2θ=1−tan2θ2tanθ​📖


    Example

    Find the exact value of tan8π​.


    Let x=tan8π​:

    tan8π​=1=1−x22x​

    Thus

    x2+2x−1=0
    x=2−2±√8​=−1±√2


    And since 8π​ is in the first quadrant tan8π​ must be positive so tan8π​=√2−1.

    Tan double angle identity

    AHL 3.10

    The double angle identity for tan states that

    tan2θ=1−tan2θ2tanθ​📖


    Example

    Find the exact value of tan8π​.


    Let x=tan8π​:

    tan8π​=1=1−x22x​

    Thus

    x2+2x−1=0
    x=2−2±√8​=−1±√2


    And since 8π​ is in the first quadrant tan8π​ must be positive so tan8π​=√2−1.

    Unit circleTrig functionsTrig equationsIdentitiesHL functionsHL Identities