2. Questions Bank
  3. JEE Main & Advanced
  4. Mathematics
  5. Trigonometric Equations

JEE Main & Advanced Mathematics Trigonometric Equations Question Bank Solution of trigonometrical equations

  • question_answer
    The solution of the equation \[\left| \,\begin{matrix}    \cos \theta  & \sin \theta  & \cos \theta   \\    -\sin \theta  & \cos \theta  & \sin \theta   \\    -\cos \theta  & -\sin \theta  & \cos \theta   \\ \end{matrix}\, \right|=0\], is [AMU 2002]

    A) \[\theta =n\pi \]

    B) \[\theta =2n\pi \pm \frac{\pi }{2}\]

    C) \[\theta =n\pi \pm {{(-1)}^{n}}\frac{\pi }{4}\]

    D) \[\theta =2n\pi \pm \frac{\pi }{4}\]

    Correct Answer: B

    Solution :

     After solving the determinant \[2\cos \theta =0\]  Þ \[\theta =2n\pi \pm \frac{\pi }{2}\].


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