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Let f:R\rightarrow R  be defined by f(x)=\frac{x}{1+x^{2}},\: x\epsilon R.   Then the range of f is :

 

  • Option 1)

     

    R-\begin{bmatrix} -\frac{1}{2}\: ,\frac{1}{2} \end{bmatrix}

  • Option 2)

     

    R-\begin{bmatrix} -{1}\: ,\1\end{bmatrix}

  • Option 3)

     

    (-1,1)- {\left { 0 \right }}

  • Option 4)

     

    \begin{bmatrix} -\frac{1}{2}\: ,\frac{1}{2} \end{bmatrix}

Answers (1)

best_answer

 

Range of function -

All possible values of  f(x)\: \: \forall x\in domain  (f) is known as Range 

-

 

f(x)=\frac{x}{\left ( \frac{1}{x}+x \right )}

AM\geq GM

\Rightarrow \frac{1}{AM}\leq \frac{1}{GM}                   if x> 0

f(x)\leq \frac{1}{2\left ( \frac{1}{x}\times x \right )}

\Rightarrow f(x)\leq \frac{1}{2}

if \: \: \: x< 0,

-AM\geq GM

\Rightarrow f(x)\geq -\frac{1}{2}

Range of f(x)\equiv \left [ -\frac{1}{2},\frac{1}{2} \right ]


Option 1)

 

R-\begin{bmatrix} -\frac{1}{2}\: ,\frac{1}{2} \end{bmatrix}

Option 2)

 

R-\begin{bmatrix} -{1}\: ,\1\end{bmatrix}

Option 3)

 

(-1,1)- {\left { 0 \right }}

Option 4)

 

\begin{bmatrix} -\frac{1}{2}\: ,\frac{1}{2} \end{bmatrix}

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