JCECE Engineering JCECE Engineering Solved Paper-2014

  • question_answer
    The value of\[\sin \frac{\pi }{14}\sin \frac{3\pi }{14}\sin \frac{5\pi }{14}\sin \frac{7\pi }{14}\sin \frac{9\pi }{14}\sin \frac{11\pi }{14}\sin \frac{13\pi }{14}\]is equal to

    A) \[\frac{1}{8}\]                                   

    B) \[\frac{1}{16}\]

    C) \[\frac{1}{32}\]                                

    D) \[\frac{1}{64}\]

    Correct Answer: D

    Solution :

    \[\sin \frac{\pi }{14}\sin \frac{3\pi }{14}\sin \frac{5\pi }{14}\sin \frac{7\pi }{14}\sin \frac{9\pi }{14}\sin \frac{11\pi }{14}\sin \frac{13\pi }{14}\]          \[=\sin \frac{\pi }{14}\sin \frac{3\pi }{14}\sin \frac{5\pi }{14}\times 1\]         \[\times \sin \left( \pi -\frac{5\pi }{14} \right)\sin \left( \pi -\frac{3\pi }{14} \right)\sin \left( \pi -\frac{\pi }{14} \right)\]                 \[={{\left[ \sin \frac{\pi }{14}\sin \frac{3\pi }{14}\sin \frac{5\pi }{14}\sin \frac{7\pi }{14} \right]}^{2}}=\frac{1}{64}\]


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