11th Class Mathematics Sample Paper Mathematics Olympiad - Sample Paper-6

  • question_answer
    If \[\mathbf{cosec}\theta +\mathbf{cot}\theta =\frac{11}{2}\],then tan \[\theta \]is equal to:

    A)  \[\frac{1}{6}\]                         

    B)  \[\frac{3}{28}\]            

    C)  \[\frac{1}{18}\]                        

    D)  \[\frac{44}{117}\]

    Correct Answer: D

    Solution :

    [d] \[\because cosec\,\theta +cot\theta =\frac{11}{2}\]                .........(1) \[\because cose{{c}^{2}}\theta -co{{t}^{2}}\theta =1\] \[(cosec\theta +cot\theta ).(cosec\theta -cot\theta )=1\] \[cosec\theta -cot\theta =\frac{1}{\cos ec\theta +\cot \theta }\]                                                    \[=\frac{2}{11}\]                                               .........(2) \[\theta \]subtracting (1) from (2), we have \[2.cot\theta =\frac{11}{2}-\frac{2}{11}\]     \[=2.cot\theta =\frac{121-4}{22}\] \[cot\theta =\frac{117}{44}\]               \[=tan\theta =\frac{44}{117}\]. Hence, option [d] is correct.


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