SSC SSC CHSL TIER-I Solved Paper Held on 09.01.2017

  • question_answer
    \[\left[ \frac{\sin A}{(1+cos\,A)} \right]+\left[ \frac{(1+cos\,A)}{\sin A} \right]\]is

    A)  2 sec A

    B)  2 cosec A

    C)  2 tan A

    D)  2 cot A

    Correct Answer: B

    Solution :

     Expression \[=\frac{\sin A}{1+\cos A}+\frac{1+\cos A}{\sin A}\] \[=\frac{{{\sin }^{2}}A+{{(1+cosA)}^{2}}}{\operatorname{sinA}(1+cosA)}\] \[=\frac{{{\sin }^{2}}A+1+2\cos A+{{\cos }^{2}}A}{\sin A(1+cosA)}\] \[=\frac{{{\sin }^{2}}A+{{\cos }^{2}}A+1+2\cos A}{\sin A(1+cosA)}\] \[=\frac{2+2\cos A}{\sin A(1+cosA)}\] \[=\frac{2(1+cosA)}{\operatorname{sinA}(1+cosA)}=\frac{2}{\sin A}\] \[=2\cos ecA\]


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