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    I am stuck on this question
    1-(sinθ tanθ )/(1+secθ )≡cosθ

    Help would be much appreciated
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    (Original post by achu2k11)
    I am stuck on this question
    1-(sinθ tanθ )/(1+secθ )≡cosθ

    Help would be much appreciated
    What have you tried?
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    First write tan in terms of sin and cos, and sec as 1/cos it should make things more obvious
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    (Original post by TenOfThem)
    I assume that you are trying to prove the identity

    Multiply out the brackets and see what happens
    Isn't it a fraction?
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    (Original post by joostan)
    Isn't it a fraction?
    oh yeah

    missed the /

    eyesight is not what it used to be
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    (Original post by achu2k11)
    I am stuck on this question
    1-(sinθ tanθ )/(1+secθ )≡cosθ

    Help would be much appreciated

    Write all the parts using Sine and Cosine

    Do you know how to get rid of a fraction in a fraction
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    i am still need help on it
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    (Original post by achu2k11)
    i am still need help on it
    So:
    \ 1 -\dfrac{\sin(\theta)\tan(\theta)}  {1+\sec(\theta)} \equiv \cos(\theta)

\Rightarrow 1 -\dfrac{\sin(\theta)\frac{\sin(\t  heta)}{\cos(\theta)}}{1+\frac{1}  {\cos(\theta)}} \equiv \cos(\theta)

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    So what happens if you multiply the LHS by
    \dfrac{\cos(\theta)}{\cos(\theta  )}?
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    (Original post by achu2k11)
    i am still need help on it
    Start by multiplying numerator and denominator of your fraction by cos \theta
 
 
 
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