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Math Help - tan etc

  1. #1
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    tan etc

    Show that equation 3tanѲ = 2cosѲ

    may be written as 2sinēѲ + 3sinѲ - 2 = 0






    thanks

    i think i started it:

    3tanѲ = 2cosѲ

    3sinѲ/cosѲ = 2(1-sinѲ)

    3sinѲ/cosѲ = 2 - 2sinѲ

    now i'm stuck
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by gracey View Post
    Show that equation 3tanѲ = 2cosѲ

    may be written as 2sinēѲ + 3sinѲ - 2 = 0






    thanks

    i think i started it:

    3tanѲ = 2cosѲ

    3sinѲ/cosѲ = 2(1-sinѲ)

    3sinѲ/cosѲ = 2 - 2sinѲ

    now i'm stuck
    cos x is NOT equal to 1 - sin x. learn your identities.

    when you get to the 3sin(x)/cos(x) = 2cos(x) line, multiply through by cos(x), then replace (cos(x))^2 with 1 - (sin(x))^2 and the rest is routine
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  3. #3
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     \frac{3sin x}{\cos x} = 2  \cos x

    multiply by cosx
     3sin x = 2  \cos^2 x
     3sin x = 2  (1- \sin^2 x)
    ... continue


    Bobak

    Edit: Jhevon beat me, gosh i wish there was a feature saying who is reply while your typing.
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  4. #4
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by bobak View Post
    gosh i wish there was a feature saying who is reply while your typing.
    i asked about that once upon a time, it seems everyone has forgotten about it

    i'll bring up the issue with the administrators again. *yawn* ...later ...
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