मराठी

The value of f (0), so that the function f ( x ) = √ a 2 − a x + x 2 − √ a 2 + a x + x 2 √ a + x − √ a − x becomes continuous for all x, given by - Mathematics

Advertisements
Advertisements

प्रश्न

The value of f (0), so that the function 

\[f\left( x \right) = \frac{\sqrt{a^2 - ax + x^2} - \sqrt{a^2 + ax + x^2}}{\sqrt{a + x} - \sqrt{a - x}}\]   becomes continuous for all x, given by

पर्याय

  • a3/2

  • a1/2 

  • a1/2 

  • a3/2

MCQ

उत्तर

\[- a^\frac{1}{2}\]

Given: 

\[f\left( x \right) = \frac{\sqrt{a^2 - ax + x^2} - \sqrt{a^2 + ax + x^2}}{\sqrt{a + x} - \sqrt{a - x}}\]

\[\Rightarrow f\left( x \right) = \frac{\left( \sqrt{a^2 - ax + x^2} - \sqrt{a^2 + ax + x^2} \right)\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)}{\left( \sqrt{a + x} - \sqrt{a - x} \right)\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)}\]
\[ \Rightarrow f\left( x \right) = \frac{\left( a^2 - ax + x^2 - \left( a^2 + ax + x^2 \right) \right)}{\left( \sqrt{a + x} - \sqrt{a - x} \right)\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)}\]
\[ \Rightarrow f\left( x \right) = \frac{\left( - 2ax \right)\left( \sqrt{a + x} + \sqrt{a - x} \right)}{\left( \sqrt{a + x} - \sqrt{a - x} \right)\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)\left( \sqrt{a + x} + \sqrt{a - x} \right)}\]
\[ \Rightarrow f\left( x \right) = \frac{\left( - 2ax \right)\left( \sqrt{a + x} + \sqrt{a - x} \right)}{\left( a + x - a + x \right)\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)}\]
\[ \Rightarrow f\left( x \right) = \frac{\left( - 2ax \right)\left( \sqrt{a + x} + \sqrt{a - x} \right)}{\left( 2x \right)\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)}\]
\[ \Rightarrow f\left( x \right) = \frac{- a\left( \sqrt{a + x} + \sqrt{a - x} \right)}{\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)}\]

If  \[f\left( x \right)\]  is continuous for all x, then it will be continuous at x = 0 as well. 

So, if  \[f\left( x \right)\]  is continuous at x = 0, then

 is continuous at x = 0, then
\[\lim_{x \to 0} f\left( x \right) = f\left( 0 \right)\]
\[\Rightarrow \lim_{x \to 0} \left[ \frac{- a\left( \sqrt{a + x} + \sqrt{a - x} \right)}{\left( \sqrt{a^2 - ax + x^2} + \sqrt{a^2 + ax + x^2} \right)} \right] = f\left( 0 \right)\]
\[ \Rightarrow \left[ \frac{- 2a\left( \sqrt{a} \right)}{\left( \sqrt{a^2} + \sqrt{a^2} \right)} \right] = f\left( 0 \right)\]
\[ \Rightarrow \left[ \frac{- 2a\left( \sqrt{a} \right)}{\left( a + a \right)} \right] = f\left( 0 \right)\]
\[ \Rightarrow f\left( 0 \right) = - \sqrt{a}\]
shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 9: Continuity - Exercise 9.4 [पृष्ठ ४४]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 12
पाठ 9 Continuity
Exercise 9.4 | Q 16 | पृष्ठ ४४

व्हिडिओ ट्यूटोरियलVIEW ALL [4]

संबंधित प्रश्‍न

Determine the value of 'k' for which the following function is continuous at x = 3

`f(x) = {(((x + 3)^2 - 36)/(x - 3),  x != 3), (k,  x = 3):}`


A function f(x) is defined as 

\[f\left( x \right) = \begin{cases}\frac{x^2 - 9}{x - 3}; if & x \neq 3 \\ 6 ; if & x = 3\end{cases}\]

Show that f(x) is continuous at x = 3

 

Discuss the continuity of the following functions at the indicated point(s): (iv) \[f\left( x \right) = \left\{ \begin{array}{l}\frac{e^x - 1}{\log(1 + 2x)}, if & x \neq a \\ 7 , if & x = 0\end{array}at x = 0 \right.\]


Discuss the continuity of the following functions at the indicated point(s): 

\[f\left( x \right) = \left\{ \begin{array}{l}\frac{1 - x^n}{1 - x}, & x \neq 1 \\ n - 1 , & x = 1\end{array}n \in N \right.at x = 1\]

Discuss the continuity of the function f(x) at the point x = 1/2, where \[f\left( x \right) = \begin{cases}x, 0 \leq x < \frac{1}{2} \\ \frac{1}{2}, x = \frac{1}{2} \\ 1 - x, \frac{1}{2} < x \leq 1\end{cases}\] 


In each of the following, find the value of the constant k so that the given function is continuous at the indicated point;  

\[f\left( x \right) = \begin{cases}k( x^2 - 2x), \text{ if }  & x < 0 \\ \cos x, \text{ if }  & x \geq 0\end{cases}\] at x = 0

Find the points of discontinuity, if any, of the following functions:  \[f\left( x \right) = \begin{cases}\frac{x^4 + x^3 + 2 x^2}{\tan^{- 1} x}, & \text{ if } x \neq 0 \\ 10 , & \text{ if }  x = 0\end{cases}\]


Prove that
\[f\left( x \right) = \begin{cases}\frac{\sin x}{x} , & x < 0 \\ x + 1 , & x \geq 0\end{cases}\] is everywhere continuous.

 


Let f (x) = | x | + | x − 1|, then


Let  \[f\left( x \right) = \begin{cases}\frac{x^4 - 5 x^2 + 4}{\left| \left( x - 1 \right) \left( x - 2 \right) \right|}, & x \neq 1, 2 \\ 6 , & x = 1 \\ 12 , & x = 2\end{cases}\]. Then, f (x) is continuous on the set

 


\[f\left( x \right) = \begin{cases}\frac{\sqrt{1 + px} - \sqrt{1 - px}}{x}, & - 1 \leq x < 0 \\ \frac{2x + 1}{x - 2} , & 0 \leq x \leq 1\end{cases}\]is continuous in the interval [−1, 1], then p is equal to

 


The values of the constants ab and c for which the function  \[f\left( x \right) = \begin{cases}\left( 1 + ax \right)^{1/x} , & x < 0 \\ b , & x = 0 \\ \frac{\left( x + c \right)^{1/3} - 1}{\left( x + 1 \right)^{1/2} - 1}, & x > 0\end{cases}\] may be continuous at x = 0, are

 


Show that f(x) = |x − 2| is continuous but not differentiable at x = 2. 


Show that f(x) = x1/3 is not differentiable at x = 0.


Show that \[f\left( x \right) =\]`{(12x, -,13, if , x≤3),(2x^2, +,5, if x,>3):}` is differentiable at x = 3. Also, find f'(3).


Find whether the function is differentiable at x = 1 and x = 2 

\[f\left( x \right) = \begin{cases}x & x \leq 1 \\ \begin{array} 22 - x  \\ - 2 + 3x - x^2\end{array} & \begin{array}11 \leq x \leq 2 \\ x > 2\end{array}\end{cases}\]

If f is defined by f (x) = x2, find f'(2).


Write the number of points where f (x) = |x| + |x − 1| is continuous but not differentiable.


The function f (x) = sin−1 (cos x) is


If \[f\left( x \right) = \sqrt{1 - \sqrt{1 - x^2}},\text{ then } f \left( x \right)\text {  is }\] 


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

then at x = 0, f (x)


Find k, if f(x) =`log (1+3x)/(5x)` for x ≠ 0

                     = k                    for x = 0

is continuous at x = 0. 


Discuss continuity of f(x) =`(x^3-64)/(sqrt(x^2+9)-5)` For x ≠ 4 

= 10 for x = 4  at x = 4


Discuss the continuity of the function f at x = 0

If f(x) = `(2^(3x) - 1)/tanx`, for x ≠ 0

         = 1,   for x = 0


Examine the continuity off at x = 1, if

f (x) = 5x - 3 , for 0 ≤ x ≤ 1

       = x2 + 1 , for 1 ≤ x ≤ 2


Examine the continuity of the following function :

`{:(,f(x),=(x^2-16)/(x-4),",","for "x!=4),(,,=8,",","for "x=4):}} " at " x=4`


Discuss the continuity of function f at x = 0.
Where f(X) = `[ [sqrt ( 4 + x ) - 2 ]/ ( 3x )]`, For x ≠ 0
                  = `1/12`,                      For x = 0


Examine the continuity of the followin function : 

  `{:(,f(x),=x^2cos(1/x),",","for "x!=0),(,,=0,",","for "x=0):}}" at "x=0`   


The probability distribution function of continuous random variable X is given by
f( x ) = `x/4`,  0 < x < 2
        = 0,       Otherwise
Find P( x ≤ 1)


Find the value of the constant k so that the function f defined below is continuous at x = 0, where f(x) = `{{:((1 - cos4x)/(8x^2)",", x ≠ 0),("k"",", x = 0):}`


If f(x) = `(sqrt(2) cos x - 1)/(cot x - 1), x ≠ pi/4` find the value of `"f"(pi/4)`  so that f (x) becomes continuous at x = `pi/4`


The function f(x) = [x], where [x] denotes the greatest integer function, is continuous at ______.


y = |x – 1| is a continuous function.


f(x) = `{{:((2x^2 - 3x - 2)/(x - 2)",", "if"  x ≠ 2),(5",", "if"  x = 2):}` at x = 2


Prove that the function f defined by 
f(x) = `{{:(x/(|x| + 2x^2)",",  x ≠ 0),("k",  x = 0):}`
remains discontinuous at x = 0, regardless the choice of k.


`lim_("x" -> "x" //4) ("cos x - sin x")/("x"- "x" /4)`  is equal to ____________.


Write the number of points where f(x) = |x + 2| + |x - 3| is not differentiable.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×