prove that cos(90- theta)- sin (90-theta) ( cosec theta- sin theta) ( tan theta+ cot theta) = 1​

prove that cos(90- theta)- sin (90-theta) ( cosec theta- sin theta) ( tan theta+ cot theta) = 1​

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  1. Step-by-step explanation:

    Answer and explanation:

    To prove : \frac{\cos(90-\theta)\sec (90-\theta)\tan \theta }{\csc (90-\theta)\sin (90-\theta)\cot (90-\theta)}+\frac{\tan (90-\theta)}{\cot \theta}=2

    csc(90−θ)sin(90−θ)cot(90−θ)

    cos(90−θ)sec(90−θ)tanθ

    +

    cotθ

    tan(90−θ)

    =2

    Proof :

    Taking LHS,

    =\frac{\cos(90-\theta)\sec (90-\theta)\tan \theta }{\csc (90-\theta)\sin (90-\theta)\cot (90-\theta)}+\frac{\tan (90-\theta)}{\cot \theta}=

    csc(90−θ)sin(90−θ)cot(90−θ)

    cos(90−θ)sec(90−θ)tanθ

    +

    cotθ

    tan(90−θ)

    Applying property of trigonometry,

    \begin{gathered}\sin (90-\theta)=\cos \theta\\\cos(90-\theta)=\sin\theta\\\sec (90-\theta)=\csc\theta\\\csc (90-\theta)=\sec\theta\\\cot (90-\theta)=\tan\theta\\\tan (90-\theta)=\cot\theta\end{gathered}

    sin(90−θ)=cosθ

    cos(90−θ)=sinθ

    sec(90−θ)=cscθ

    csc(90−θ)=secθ

    cot(90−θ)=tanθ

    tan(90−θ)=cotθ

    =\frac{\sin\theta\csc\theta\tan \theta }{\sec\theta\cos\theta\tan\theta}+\frac{\cot\theta}{\cot \theta}=

    secθcosθtanθ

    sinθcscθtanθ

    +

    cotθ

    cotθ

    We know, \csc\tehta=\frac{1}{\sin\theta},\ \sec\tehta=\frac{1}{\cos\theta}csc\tehta=

    sinθ

    1

    , sec\tehta=

    cosθ

    1

    =\frac{\sin\theta\times \frac{1}{\sin\theta}\times \tan \theta }{\frac{1}{\cos\theta}\times \cos\theta\times \tan\theta}+\frac{\cot\theta}{\cot \theta}=

    cosθ

    1

    ×cosθ×tanθ

    sinθ×

    sinθ

    1

    ×tanθ

    +

    cotθ

    cotθ

    =\frac{1}{1}+1=

    1

    1

    +1

    =1+1=1+1

    =2=2

    LHS=RHS

    Hence proved

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