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Math Help - Simple Trig Identity - help

  1. #1
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    Simple Trig Identity - help

    I need help with this equation:

    sin(x)cos(x)tan(x)=1-cos^2(x)
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  2. #2
    MHF Contributor
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    Quote Originally Posted by marekd View Post
    I need help with this equation:

    sin(x)cos(x)tan(x)=1-cos^2(x)
    hi

    some hints ,

    tan x = sin x/cos x

    sin^2 x + cos^2 x=1
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  3. #3
    Member mybrohshi5's Avatar
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    Hi

    substitute \frac{sinx}{cosx} for tanx.

    This will give you

    sinx*cosx*\frac{sinx}{cosx}= 1 - cos^2x

    as you can see the cosx will cancel on the left side of the equal sign.

    This leaves you with

     sin^2x = 1 - cos^2x

    and you know the trig identity of  sin^2x + cos^2x = 1

    Does that clear everything up for you?
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  4. #4
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    Helps a lot. Thanks you guys
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