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    prove that cos 3x = 4cos^3x - 3cosx
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    Split it into cos(x+2x) and then use the double angle formulae to break it down from there.
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    Anime is bae stop doing maths
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    (Original post by JMA120122323)
    Anime is bae stop doing maths
    looool
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    (Original post by killerjayko)
    Split it into cos(x+2x) and then use the double angle formulae to break it down from there.
    will do thanks
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    It's not double, it's triple :dontknow:
 
 
 
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Updated: February 20, 2018
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