2. Solved Papers
  3. CET Karnataka Engineering

CET Karnataka Engineering CET - Karnataka Engineering Solved Paper-2000

  • question_answer
    If\[\cos A=\cos B=\cos C\]and \[A+B+C=\pi ,\]then \[\cot B\cot C\]will be equal to:

    A)  1/2                                       

    B)  5/4

    C)  \[SinA\sin B\]                  

    D) \[\cos A\cos B\]

    Correct Answer: A

    Solution :

    \[\cos A=\cos B\cos C\]and \[A+B+C=\pi \] or            \[B+C=\pi -A\] \[\Rightarrow \]               \[\cos (B+C)=\pi -A\] \[\cos B\cos C-\sin B\sin C=\cos B\cos C\] \[2\cos B\cos C=\sin B\sin C\] \[\frac{\cos B\cos C}{\sin B\sin C}=1/2\Rightarrow \cot B\cot C=1/2\]


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