Question

Let $$f:\left( {4,\,6} \right) \to \left( {6,\,8} \right)$$    be a function defined by $$f\left( x \right) = x + \left[ {\frac{x}{2}} \right]$$   (where [.] denotes the greatest integer function), then $${f^{ - 1}}\left( x \right)$$  is equal to :

A. $$x - \left[ {\frac{x}{2}} \right]$$
B. $$ - x - 2$$
C. $$x - 2$$  
D. $$\frac{1}{{x + \left[ {\frac{x}{2}} \right]}}$$
Answer :   $$x - 2$$
Solution :
$$\eqalign{ & {\text{Since }}f:\left( {4,\,6} \right) \to \left( {6,\,8} \right) \Rightarrow f\left( x \right) = x + 2 \cr & \therefore \,{f^{ - 1}}\left( x \right) = x - 2 \cr} $$

Releted MCQ Question on
Calculus >> Sets and Relations

Releted Question 1

If $$X$$ and $$Y$$ are two sets, then $$X \cap {\left( {X \cup Y} \right)^c}$$   equals.

A. $$X$$
B. $$Y$$
C. $$\phi $$
D. None of these
Releted Question 2

The expression $$\frac{{12}}{{3 + \sqrt 5 + 2\sqrt 2 }}$$    is equal to

A. $$1 - \sqrt 5 + \sqrt 2 + \sqrt {10} $$
B. $$1 + \sqrt 5 + \sqrt 2 - \sqrt {10} $$
C. $$1 + \sqrt 5 - \sqrt 2 + \sqrt {10} $$
D. $$1 - \sqrt 5 - \sqrt 2 + \sqrt {10} $$
Releted Question 3

If $${x_1},{x_2},.....,{x_n}$$    are any real numbers and $$n$$ is any positive integer, then

A. $$n\sum\limits_{i = 1}^n {{x_i}^2 < {{\left( {\sum\limits_{i = 1}^n {{x_i}} } \right)}^2}} $$
B. $$\sum\limits_{i = 1}^n {{x_i}^2 \geqslant {{\left( {\sum\limits_{i = 1}^n {{x_i}} } \right)}^2}} $$
C. $$\sum\limits_{i = 1}^n {{x_i}^2 \geqslant n{{\left( {\sum\limits_{i = 1}^n {{x_i}} } \right)}^2}} $$
D. none of these
Releted Question 4

Let $$S$$ = {1, 2, 3, 4}. The total number of unordered pairs of disjoint subsets of $$S$$ is equal to

A. 25
B. 34
C. 42
D. 41

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Sets and Relations


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