हिंदी

If F is a Real Function Satisfying F ( X + 1 X ) = X 2 + 1 X 2 for All X ∈ R − {0}, Then Write the Expression for F(X). - Mathematics

Advertisements
Advertisements

प्रश्न

If f is a real function satisfying \[f\left( x + \frac{1}{x} \right) = x^2 + \frac{1}{x^2}\]

for all x ∈ R − {0}, then write the expression for f(x).

 
 

उत्तर

Given:

\[f\left( x + \frac{1}{x} \right) = x^2 + \frac{1}{x^2}\] 

\[= x^2 + \frac{1}{x^2} + 2 - 2\]

\[= \left( x + \frac{1}{x} \right)^2 - 2\]
Thus,
\[f\left( x + \frac{1}{x} \right) = \left( x + \frac{1}{x} \right)^2 - 2\]
Hence,
f (x)  = x-  2 , where | x | ≥  2.
 
 
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Functions - Exercise 3.5 [पृष्ठ ४१]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
अध्याय 3 Functions
Exercise 3.5 | Q 2 | पृष्ठ ४१

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Let f be the subset of Z × Z defined by f = {(ab, a + b): a, b ∈ Z}. Is f a function from Z to Z: justify your answer.


If \[f\left( x \right) = \frac{x - 1}{x + 1}\] , then show that  

(i) \[f\left( \frac{1}{x} \right) = - f\left( x \right)\]

(ii) \[f\left( - \frac{1}{x} \right) = - \frac{1}{f\left( x \right)}\]


If f(x) = loge (1 − x) and g(x) = [x], then determine function:

(iii) \[\frac{f}{g}\]

 

Let f : [0, ∞) → R and g : R → R be defined by \[f\left( x \right) = \sqrt{x}\] and g(x) = x. Find f + gf − gfg and \[\frac{f}{g}\] .

 
 

If f(x) = cos [π2]x + cos [−π2x, where [x] denotes the greatest integer less than or equal to x, then write the value of f(π).


Let  \[f\left( x \right) = \frac{\alpha x}{x + 1}, x \neq - 1\] . Then write the value of α satisfying f(f(x)) = x for all x ≠ −1.

 

 


Let A = {1, 2, 3} and B = {2, 3, 4}. Then which of the following is a function from A to B? 

 


If A = {1, 2, 3} and B = {xy}, then the number of functions that can be defined from A into B is


If x ≠ 1 and \[f\left( x \right) = \frac{x + 1}{x - 1}\] is a real function, then f(f(f(2))) is

 

If f : R → R and g : R → R are defined by f(x) = 2x + 3 and g(x) = x2 + 7, then the values of x such that g(f(x)) = 8 are


If : [−2, 2] → R is defined by \[f\left( x \right) = \begin{cases}- 1, & \text{ for }  - 2 \leq x \leq 0 \\ x - 1, & \text{ for }   0 \leq x \leq 2\end{cases}\] , then
{x ∈ [−2, 2] : x ≤ 0 and f (|x|) = x} =

 

If \[3f\left( x \right) + 5f\left( \frac{1}{x} \right) = \frac{1}{x} - 3\]  for all non-zero x, then f(x) =


The domain of the function

\[f\left( x \right) = \sqrt{2 - 2x - x^2}\] is
 

If f(m) = m2 − 3m + 1, find `f(1/2)`


Check if the following relation is a function.


Which sets of ordered pairs represent functions from A = {1, 2, 3, 4} to B = {−1, 0, 1, 2, 3}? Justify.

{(1, 2), (2, −1), (3, 1), (4, 3)}


Which sets of ordered pairs represent functions from A = {1, 2, 3, 4} to B = {−1, 0, 1, 2, 3}? Justify.

{(1, 3), (4, 1), (2, 2)}


Which sets of ordered pairs represent functions from A = {1, 2, 3, 4} to B = {−1, 0, 1, 2, 3}? Justify.

{(1, 1), (2, 1), (3, 1), (4, 1)}


Check if the relation given by the equation represents y as function of x:

x2 − y = 25


Find the domain and range of the following function.

g(x) = `(x + 4)/(x - 2)`


Find the domain and range of the follwoing function.

h(x) = `sqrt(x + 5)/(5 + x)`


Find the domain and range of the following function.

f(x) = `sqrt((x - 2)(5 - x)`


Express the area A of a square as a function of its side s


Express the area A of a square as a function of its perimeter P


Let f be a subset of Z × Z defined by f = {(ab, a + b) : a, b ∈ Z}. Is f a function from Z to Z? Justify?


Express the following logarithmic equation in exponential form

ln e = 1


Write the following expression as sum or difference of logarithm

`log (sqrt(x) root(3)(y))`


Write the following expression as sum or difference of logarithm

In `(("a"^3 ("a" - 2)^2)/sqrt("b"^2 + 5))`


Answer the following:

Find whether the following function is one-one

f : R → R defined by f(x) = x2 + 5


Answer the following:

A function f is defined as f(x) = 4x + 5, for – 4 ≤ x < 0. Find the values of f(–1), f(–2), f(0), if they exist


Answer the following:

Let f : R → R be given by f(x) = x + 5 for all x ∈ R. Draw its graph


If f(x) = `x^3 - 1/x^3`, then `f(x) + f(1/x)` is equal to ______.


Find the range of the following functions given by f(x) = `3/(2 - x^2)`


If f(x) = `(x - 1)/(x + 1)`, then show that `f(1/x)` = – f(x)


If f(x) = y = `(ax - b)/(cx - a)`, then prove that f(y) = x.


The range of the function y = `1/(2 - sin3x)` is ______.


The expression \[\begin{array}{cc}\log_p\log_p\sqrt[p]{\sqrt[p]{\sqrt[p]{\text{...........}\sqrt[p]{p}}}}\\
\phantom{...........}\ce{\underset{n radical signs}{\underline{\uparrow\phantom{........}\uparrow}}}
\end{array}\]where p ≥ 2, p ∈ N; ∈ N when simplified is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×