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Question: Answered & Verified by Expert
If \( f: R \rightarrow R \) is defined by \( f(x)=\frac{x}{x^{2}+1} \) find \( f(f(2)) \)
MathematicsThree Dimensional GeometryKCETKCET 2015
Options:
  • A \( \frac{1}{29} \)
  • B \( \frac{10}{29} \)
  • C \( \frac{29}{10} \)
  • D \( \frac{5}{29} \)
Solution:
2906 Upvotes Verified Answer
The correct answer is: \( \frac{10}{29} \)
Given that, \( f(x)=\frac{x}{x^{2}+1} \rightarrow(1) \)
At \( x=2 \), we have \( f(2)=\frac{2}{2^{2}+1}=\frac{2}{5} \)
So, \( f(f(2))=\frac{\frac{2}{5}}{\left(\frac{2}{5}\right)^{2}+1} \)
\( =\frac{\frac{2}{5}}{\frac{4}{25}+1}=\frac{10}{4+25}=\frac{10}{29} \)

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