SSC Sample Paper SSC CHSL (10+2) Sample Test Paper-11

  • question_answer
    If \[\tan \,\,\theta +\sec \theta =m,\] then \[\sec \theta \] is equal to?

    A)  \[\frac{{{m}^{2}}-1}{2m}\]                             

    B)  \[\frac{{{m}^{2}}+1}{2m}\]

    C)  \[\frac{m+1}{m}\]                         

    D)  \[\frac{{{m}^{2}}+1}{m}\]

    Correct Answer: B

    Solution :

     \[\tan \theta +\sec \theta =m\] \[\Rightarrow \,\,\sec \theta =m-\tan \theta \] On squaring both sides, we get \[{{\left( \sec \theta  \right)}^{2}}={{\left( m-\tan \theta  \right)}^{2}}\] \[\Rightarrow \,\,{{\sec }^{2}}\theta ={{m}^{2}}+{{\tan }^{2}}\theta -2m\,\tan \theta \] \[\Rightarrow \,{{\sec }^{2}}\theta -{{\tan }^{2}}\theta ={{m}^{2}}-2m\,\tan \theta \] \[\Rightarrow \,\,1={{m}^{2}}-2m\,\tan \theta \]                 \[(\because \,\,\,{{\sec }^{2}}\theta -{{\tan }^{2}}\theta =1)\] \[\Rightarrow \,\,\tan \theta =\frac{{{m}^{2}}-1}{2m}\] On putting the value of \[tan\text{ }\theta \]in initial equation, we get \[\frac{{{m}^{2}}-1}{2m}+\sec \theta =m\Rightarrow \sec \theta =m-\frac{{{m}^{2}}-1}{2m}\] \[\therefore \,\,\sec \theta =\frac{2{{m}^{2}}-{{m}^{2}}+1}{2m}=\]


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