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Question: Answered & Verified by Expert
If $f$ is a relation from set of positive real number to the set of positive real numbers defined by $f(x)=3 x^2-2$, then $f$ is
MathematicsFunctionsAP EAMCETAP EAMCET 2022 (07 Jul Shift 2)
Options:
  • A one-one but not onto
  • B onto but not one-one
  • C a bijection
  • D not a function
Solution:
2011 Upvotes Verified Answer
The correct answer is: not a function
(w) $f: R_{+} \rightarrow R_{+}$
$$
f(x)=3 x^2-2
$$

As
$$
\begin{aligned}
& x \in(0, \infty) \\
& 3 x^2-2 \in(-2, \infty)
\end{aligned}
$$

But co-domain of $f$ is $R_{+}$.
Hence, $f$ is not a function.

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