JEE Main & Advanced Mathematics Trigonometric Identities Question Bank Self Evaluation Test - Trigonometric Function

  • question_answer
    The general solution of the equation \[{{\sin }^{50}}x-{{\cos }^{50}}x=1\]is

    A) \[2n\pi +\frac{\pi }{2}\]        

    B) \[2n\pi +\frac{\pi }{3}\]

    C) \[n\pi +\frac{\pi }{2}\]         

    D) \[n\pi +\frac{\pi }{3}\]

    Correct Answer: B

    Solution :

    We have, \[{{\sin }^{50}}x-{{\cos }^{50}}x=1\Rightarrow {{\sin }^{50}}x=1+{{\cos }^{50}}x\] Since \[{{\sin }^{50}}x\le 1\] and \[1+{{\cos }^{50}}x\ge 1\]. therefore, the two sides are equal only if \[{{\sin }^{50}}x=1=1+{{\cos }^{50}}x\] i.e \[{{\sin }^{50}}x=1\] and \[{{\cos }^{50}}x=0\] \[\therefore \,\,\,x=2n\pi +\frac{\pi }{2},\,\,n\in I\].


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