Home> Questions>Q 763
Next
Answered

AcedStudy Latest Questions

godwin_ibrahim
  • 0
Tyro
Asked: 2020-11-25T20:35:52+00:00 In:

Without using table, in a simplified surd form, find the value \dfrac{1+\cos 240^{0}}{1-\cos 240^{0}}

  • 0

Without using table, in a simplified surd form, find the value \dfrac{1+\cos 240^{0}}{1-\cos 240^{0}}

trigonometry- surd form

You must login to add an answer.

Need An Account,

1 Answer

  2. Sengemegz
    Best Answer
    Moderator

    \dfrac{1+\cos 240^{0}}{1-\cos 240^{0}}
    240 falls in the third quadrant and cosine is negative
    \Rightarrow \cos 240^{0}=-\cos (240-180)^{0}
    \Rightarrow -\cos 60^{0}=-\dfrac{1}{2}
    hence
    \Rightarrow \dfrac{1+\cos 240^{0}}{1-\cos 240^{0}}=\dfrac{1+(-\dfrac{1}{2})}{1-(-\dfrac{1}{2})}
    \Rightarrow \dfrac{2-1}{2}\div \dfrac{2+1}{2}
    \Rightarrow \dfrac{1}{2}\times \dfrac{2}{3}=\dfrac{1}{3}

Related Questions