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

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

  • question_answer
    The number of solution of \[\tan x+\sec x=2\cos x\] in \[(0,2\pi )\]is

    A) 2                     

    B) 3   

    C) 0         

    D) 1

    Correct Answer: B

    Solution :

    The given equation is \[\tan x+\sec x=2\cos x;\] \[\Rightarrow \,\,\sin x+1=2{{\cos }^{2}}x\Rightarrow \sin x+1=2(1-{{\sin }^{2}}x);\] \[\Rightarrow \,\,\,2{{\sin }^{2}}x+\sin x-1=0;\] \[\Rightarrow \,\,\,(2\sin x-1)(sinx+1)=0\Rightarrow sin\,x=\frac{1}{2},-1.;\] \[\Rightarrow \,\,x=30{}^\circ ,150{}^\circ ,270{}^\circ .\]


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