A) \[\{\,\phi \,\}\]
B) \[\phi \]
C) \[\{\,5\,\}\]
D) \[\{\,-5,\,\,5\,\}\]
Correct Answer: B
Solution :
Let \[{{f}^{-1}}(-5)=x.\] Then, \[f(x)=-5\] \[\Rightarrow \]\[{{x}^{2}}+1=-\,5\] \[\Rightarrow \]\[{{x}^{2}}=-\,6\] \[\Rightarrow \]\[x=\pm \sqrt{-6}\] which does not belong to R. \[\therefore \]\[{{f}^{-1}}(-5)=\phi \]You need to login to perform this action.
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