Manipal Engineering Manipal Engineering Solved Paper-2012

  • question_answer
    The value of\[\sin ({{22}^{o}}30)\]is

    A) \[\sqrt{\frac{\sqrt{2}+1}{2\sqrt{2}}}\]

    B)                       \[\sqrt{\sqrt{2}-1}\]

    C) \[\sqrt{\frac{\sqrt{2}-1}{2\sqrt{2}}}\]    

    D)         None of these

    Correct Answer: C

    Solution :

    We know,                 \[{{\sin }^{2}}A=\left( \frac{1-\cos 2A}{2} \right)\] \[\Rightarrow \]               \[{{\sin }^{2}}(22{}^\circ 30)=\frac{1-\cos {{45}^{o}}}{2}\]                 \[=\frac{\left( 1-\frac{1}{\sqrt{2}} \right)}{2}\]                 \[=\frac{\sqrt{2}-1}{2\sqrt{2}}\] \[\Rightarrow \]               \[\sin (22{}^\circ 30)=\sqrt{\frac{\sqrt{2}-1}{2\sqrt{2}}}\]


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