JEE Main & Advanced Sample Paper JEE Main Sample Paper-6

  • question_answer
    Total number of solutions of \[|\cot x|=\cot x+\frac{1}{\sin x},x\in [0,3\pi ]\] is equal to

    A)  1                                            

    B)  3

    C)  2                                            

    D)  zero

    Correct Answer: C

    Solution :

    \[|\cot x|=\cot x+\frac{1}{\sin x}\] Let \[\cot x>0\Rightarrow \cot x=\cot x+\frac{1}{\sin x}=0\] \[\Rightarrow \]\[\frac{1}{\sin x}=0,\] Let\[\cot x\le 0\] \[\Rightarrow \]\[-\cot x=\cot x+\frac{1}{\sin x}\]\[\Rightarrow \]\[-2\cot x=\frac{1}{\sin x}\] \[\Rightarrow \]\[\cos x=-\frac{1}{2}\Rightarrow x=\frac{2\pi }{3},\frac{8\pi }{3}\] \[\therefore \]The number of solutions are 2.


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