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Math Help - identity

  1. #1
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    identity

    show that:

    a) (1 - sin^2[a])(1 + tan^2[a]) = 1

    b) (1 - cos^2[a])/(sec^2[a] - 1) = 1 - sin^2[a]

    i would be greatfull to recieve step by step answers
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  2. #2
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    Quote Originally Posted by T_o_M View Post
    show that:

    a) (1 - sin^2[a])(1 + tan^2[a]) = 1
    Use pythagoren identities,

    1-sin^2a=cos^2a

    And

    1+tan^2a=sec^2a=1/cos^2a

    When you multiply them out you get,
    (cos^2a)(1/cos^2a)=1
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