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Dean
Dean asked in Science & MathematicsMathematics · 4 years ago

sec(x)sin(x)-2sin(x)=0 My textbook is giving confusing answers. Please help?

I already found the solutions 0 and pi. However, my text book lists those solutions AND the following: pi/3, 5pi/3. How would those be solutions. Can somebody please help me with this? Thanks

3 Answers

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  • ?
    Lv 7
    4 years ago
    Favorite Answer

    sec x sin x - 2sin x = 0

    Either sin x = 0 (which gives your answers) or we can divide both sides by it to give

    sec x - 2 = 0

    sec x = 2

    1 / cos x = 2

    cos x = 1/2

    which gives x = pi/3 or 5pi/3

  • ?
    Lv 7
    4 years ago

    Sec(x)sin(x)-2sin(x)=0

    sin x( Sec(x) - 2)=0

    Ur solutions corresond to sin x = 0

    is sec x - 2= 0

    then 1/cos x - 2 =0

    ( 1 - 2cos x ) / cos x = 0

    or 1 = 2 cos x

    cos x = 1/2

    or x = pi/3 , 2pi-pi/3

  • Como
    Lv 7
    4 years ago

    sin x [ sec x - 2 ] = 0

    sin x [ 1/cos x - 2 ] = 0

    sin x = 0 , cos x = 1/2

    x = 0 , π , π/3 , 5π/3

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