Railways Sample Paper RRBs Assistant Loco Pilot and Technician CBT STAGE-I Sample Paper-7

  • question_answer
    If \[3\tan \,\theta =4,\]then\[\sqrt{\frac{1-\sin \theta }{1+\sin \theta }}\]  is equal to

    A)  \[\frac{1}{2}\]             

    B)  \[\frac{2}{3}\]

    C)  \[\frac{1}{3}\]

    D)  None of these

    Correct Answer: C

    Solution :

    \[\because \] \[3\tan \theta =4\Rightarrow \tan \theta =\frac{4}{5}\] \[\because \] \[\sqrt{\frac{1-\sin \theta }{1+\sin \theta }}=\sqrt{\frac{1-\sin \theta }{1+\sin \theta }\times \frac{1-\sin \theta }{1-\sin \theta }}=\frac{1-\sin \theta }{\cos \theta }\] \[=\sec \theta -\tan \theta =\sqrt{1+{{\tan }^{2}}\theta }-\tan \theta \] \[=\sqrt{1+{{\left( \frac{4}{3} \right)}^{2}}}-\frac{4}{3}=\sqrt{1+\left( \frac{16}{9} \right)}-\frac{4}{3}=\frac{5}{3}-\frac{4}{3}=\frac{1}{3}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner