CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2001

  • question_answer
    If g is the inverse function of\[f\]and \[f(x)=\frac{1}{1+{{x}^{n}}},\]then\[g(x)\]is equal to:

    A)  \[i+{{(g(x))}^{n}}\]        

    B)         \[1-g(x)\]

    C)  \[1+g(x)\]          

    D)         \[1-{{(g(x))}^{n}}\]

    E)  \[{{(g(x))}^{n}}\]

    Correct Answer: A

    Solution :

    \[\because \]\[y=f(x),\]then\[x={{f}^{-1}}(y)\] i,e., \[x=g(y)\] On differentiating, w. r. t.\[x,\]we get \[\Rightarrow \]               \[1=g(y)\frac{dy}{dx}=g(y)\frac{1}{1+{{x}^{n}}}\] \[\Rightarrow \]               \[g(y)=1+{{x}^{n}}=1+{{[g(y)]}^{n}}\] \[\Rightarrow \]               \[g(x)=1+{{[g(x)]}^{n}}\]


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