Railways Sample Paper RRBs Assistant Loco Pilot and Technician CBT STAGE-I Sample Paper-20

  • question_answer
    If\[x=\frac{\sin \theta \cdot \cos \,\,(90{}^\circ -\theta )+\cos \theta \cdot \sin \,\,(90{}^\circ -\theta )}{\tan \theta \cdot \,(90{}^\circ -\theta )\cdot \sin \,\,(90{}^\circ -\theta )}\] what will be the value of x ?

    A)  1                    

    B)  \[-1\]

    C)  2                    

    D)        \[-\,2\]

    Correct Answer: A

    Solution :

    \[x=\frac{\sin \theta \cos (90{}^\circ -\theta )+\cos \theta \sin (90{}^\circ -\theta )}{\tan \theta \sec (90{}^\circ -\theta )\sin (90{}^\circ -\theta )}\] \[=\frac{\sin \theta \sin \theta +\cos \theta \cos \theta }{\tan \theta \cos \theta \cdot \cos ec\theta }\] \[=\frac{{{\sin }^{2}}\theta +{{\cos }^{2}}\theta }{\frac{\sin \theta }{\cos \theta }\cdot \cos \theta \cdot \frac{1}{\sin \theta }}\] \[=\frac{1}{\frac{\sin \theta \cos \theta }{\cos \theta \sin \theta }}=1\]


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