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    I have the question from the WJEC May 2012 C2 Past Paper:
    Find all values of Φ in the range 0° ≤ Φ ≤ 360° satisfying cosΦ - 5sinΦ = 0

    I know that you can use the identity sinθ ÷ cosθ ≡ tanθ, but I don't know how to rearrange the equation given in order to use the identity. Can someone talk me through the rearranging steps please?

    Many thanks.
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    (Original post by Kaimund600)
    I have the question from the WJEC May 2012 C2 Past Paper:
    Find all values of Φ in the range 0° ≤ Φ ≤ 360° satisfying cosΦ - 5sinΦ = 0

    I know that you can use the identity sinθ ÷ cosθ ≡ tanθ, but I don't know how to rearrange the equation given in order to use the identity. Can someone talk me through the rearranging steps please?

    Many thanks.
    5\sin \theta = \cos \theta. Move over the -5\sin \theta to the other side.

    5\frac{\sin \theta}{\cos \theta} = 1. Divide by \cos \theta.
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    (Original post by Zacken)
    5\sin \theta = \cos \theta.

    5\frac{\sin \theta}{\cos \theta} = 1
    It looks so simple now. Thank you very much!
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    add 5sinx to both sides:
    cosx=5sinx
    divide both sides by cosx
    1=5(sinx/cosx)
    1=5tanx
    divide both sides by 5
    1/5=tanx
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    (Original post by Kaimund600)
    It looks so simple now. Thank you very much!
    You're very welcome. :cool:
 
 
 
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