JEE Main & Advanced AIEEE Solved Paper-2007

  • question_answer
    The function\[+6C{{l}^{-}}(aq)+3{{H}_{2}}(g)\]is an increasing function in       AIEEE  Solved  Paper-2007

    A)  \[6\text{ }L\text{ }HCl(aq)\]      

    B)          \[3\text{ }L\text{ }{{H}_{2}}(g)\]

    C)                         \[33.6\,L\,{{H}_{2}}(g)\]              

    D)        \[Al\]

    Correct Answer: B

    Solution :

    Differentiate w.r.t.\[x\]and it\[f'(x)>0\]for given interval, then the function is increasing. \[\because \]\[f(x)={{\tan }^{-1}}(\sin x+\cos x)\] \[\therefore \]\[f'(x)=\frac{1}{1+{{(\sin x+\cos x)}^{2}}}(\cos x-\sin x)\] \[=\frac{\sqrt{2}\cos \left( x+\frac{\pi }{4} \right)}{1+{{(\sin x+\cos x)}^{2}}}\] \[f(x)\]is increasing, if\[-\frac{\pi }{2}<x+\frac{\pi }{4}<\frac{\pi }{2}\] \[\Rightarrow \]\[-\frac{3\pi }{4}<x<\frac{\pi }{4}\] Hence,\[f(x)\]is increasing when \[x\in \left( -\frac{\pi }{2},\frac{\pi }{4} \right)\]


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