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    In the diagram AB = 6 cm is the diameter of the circle and BT is the tangent to the circle at B. The chord AC is extended to meet this tangent at D and angle DAB = theta
    a) Show that CD = 6 (sec[theta]-cost[theta]




    So i have seen the answer and how to get to it. I understand that

    cos theta = AB/AD.

    what i can't understand is why

    cos theta = AC/6.

    Thanks a detailed work through and explanation would be appreciated.
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    Never mind. Found the right angle triangle ABC. whoops
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    Wait, are you seriously doing A Level Math at 3am in the morning?
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    (Original post by postexamtalk)
    Wait, are you seriously doing A Level Math at 3am in the morning?
    #RoadToA*
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    (Original post by postexamtalk)
    Wait, are you seriously doing A Level Math at 3am in the morning?
    Haha, where i am it was 5:00am.
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    (Original post by Paranoid_Glitch)
    Haha, where i am it was 5:00am.
    Ohhh 5am, that totally makes it normal
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    You did it wrong. The answer was 4.72.
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    (Original post by MersennePrime)
    You did it wrong. The answer was 4.72.
    Sorry which part?
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    (Original post by postexamtalk)
    Ohhh 5am, that totally makes it normal
    Have to get that A* though.
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    (Original post by Paranoid_Glitch)
    Sorry which part?
    The part before you divide the equation by 3.
 
 
 
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