हिंदी

Discuss the Continuity of the Following Functions. If the Function Have a Removable Discontinuity, Redefine the Function So as to Remove the Discontinuity - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

Discuss the continuity of the following functions. If the function have a removable discontinuity, redefine the function so as to remove the discontinuity

`f(x)=(4^x-e^x)/(6^x-1)`  for x ≠ 0

         `=log(2/3) ` for x=0

योग

उत्तर

f(0) = log `(2/3)`      .....Given .....(1)

`lim_(x->0^-f(x))=lim_(x->0^-)(4^x-e^x)/(6^x-1)`


`= lim_(x->0) ((4^x - 1) - (e^x - 1))/(6^x - 1) `

 

`lim_(x->0) ((4^x - 1)/x - (e^x - 1)/x)/((6^x - 1)/x)`  .....[x → 0 , x ≠ 0]

 

`lim_(x->0) (lim_(x->0)(4^x - 1)/x - lim_(x->0)(e^x - 1)/x)/(lim_(x->0)(6^x - 1)/x)` 


`=((log4) - 1)/log6`    .......`[because lim_(x->0) (a^x - 1)/x = log e]`

`therefore lim_(x->0) f(x) = ((log4) - loge)/log6`

`therefore lim_( x ->0) = [log4]/[loge.log6]`

`therefore lim_( x ->0) = [log4]/[1.log6]`

`therefore lim_( x ->0) = log(2/3)`

From (1) and (2) , lim_(x->0) f(x) ≠ f(0)

∴ f is discontinuous at x = 0

Here lim_(x->0)  f(x) exists but not equal to f(0). Hence , the discontinuity at x = 0 is removable and can be removed by redefining the function as follows :

`f(x)=(4^x-e^x)/(6^x-1)`  for x ≠ 0

         `=log(2/3) ` for x=0

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
2015-2016 (March)

APPEARS IN

संबंधित प्रश्न

Show that the function `f(x)=|x-3|,x in R` is continuous but not differentiable at x = 3.


Find the values of p and q for which

f(x) = `{((1-sin^3x)/(3cos^2x),`

is continuous at x = π/2.


Find all points of discontinuity of f, where f is defined by `f (x) = {(x/|x|, if x<0),(-1, if x >= 0):}`


Find the points of discontinuity of f, where `f (x) = {(sinx/x, if x<0),(x + 1, if x >= 0):}`


Examine the continuity of f, where f is defined by `f(x) = {(sin x - cos x, if x != 0),(-1, "," if x = 0):}`


Using mathematical induction prove that  `d/(dx) (x^n) = nx^(n -1)` for all positive integers n.


Determine the value of the constant 'k' so that function f(x) `{((kx)/|x|, ","if  x < 0),(3"," , if x >= 0):}` is continuous at x = 0


Find the value of constant ‘k’ so that the function f (x) defined as

f(x) = `{((x^2 -2x-3)/(x+1), x != -1),(k, x != -1):}`

is continous at x = -1


Show that the function f(x) = `{(x^2, x<=1),(1/2, x>1):}` is continuous at x = 1 but not differentiable.


Prove that the function 

\[f\left( x \right) = \begin{cases}\frac{x}{\left| x \right| + 2 x^2}, & x \neq 0 \\ k , & x = 0\end{cases}\]  remains discontinuous at x = 0, regardless the choice of k.

For what value of λ is the function 
\[f\left( x \right) = \begin{cases}\lambda( x^2 - 2x), & \text{ if }  x \leq 0 \\ 4x + 1 , & \text{  if } x > 0\end{cases}\]continuous at x = 0? What about continuity at x = ± 1?


Find the relationship between 'a' and 'b' so that the function 'f' defined by 

\[f\left( x \right) = \begin{cases}ax + 1, & \text{ if }  x \leq 3 \\ bx + 3, & \text{ if } x > 3\end{cases}\] is continuous at x = 3.

 


Find the points of discontinuity, if any, of the following functions: \[f\left( x \right) = \begin{cases}2x , & \text{ if }  & x < 0 \\ 0 , & \text{ if }  & 0 \leq x \leq 1 \\ 4x , & \text{ if }  & x > 1\end{cases}\]


In the following, determine the value of constant involved in the definition so that the given function is continuou: 

\[f\left( x \right) = \begin{cases}\frac{k \cos x}{\pi - 2x} , & x < \frac{\pi}{2} \\ 3 , & x = \frac{\pi}{2} \\ \frac{3 \tan 2x}{2x - \pi}, & x > \frac{\pi}{2}\end{cases}\]

Discuss the Continuity of the F(X) at the Indicated Points : F(X) = | X − 1 | + | X + 1 | at X = −1, 1.


 Show that the function `f(x) = |x-4|, x ∈ R` is continuous, but not diffrent at x = 4. 


Prove that `1/2 "cos"^(-1) ((1-"x")/(1+"x")) = "tan"^-1 sqrt"x"`


Find all points of discontinuity of the function f(t) = `1/("t"^2 + "t" - 2)`, where t = `1/(x - 1)`


`lim_("x" -> pi/2)` [sinx] is equal to ____________.


The number of discontinuous functions y(x) on [-2, 2] satisfying x2 + y2 = 4 is ____________.


If f(x) `= sqrt(4 + "x" - 2)/"x", "x" ne 0` be continuous at x = 0, then f(0) = ____________.


`lim_("x"-> 0) sqrt(1/2 (1 - "cos"  2"x"))/"x"` is equal to


The domain of the function f(x) = `""^(24 - x)C_(3x - 1) + ""^(40 - 6x)C_(8x - 10)` is


The function `f(x) = (x^2 - 25)/(x + 5)` is continuous at x =


The point of discountinuity of the function `f(x) = {{:(2x + 3",", x ≤ 2),(2x - 3",", x > 2):}` is are


Sin |x| is a continuous function for


If function f(x) = `{{:((asinx + btanx - 3x)/x^3,",", x ≠ 0),(0,",", x = 0):}` is continuous at x = 0 then (a2 + b2) is equal to ______.


If functions g and h are defined as

g(x) = `{{:(x^2 + 1, x∈Q),(px^2, x\cancel(∈)Q):}`

and h(x) = `{{:(px, x∈Q),(2x + q, x\cancel(∈)Q):}`

If (g + h)(x) is continuous at x = 1 and x = 3, then 3p + q is ______.


If f(x) = `{{:(cos ((π(sqrt(1 + x) - 1))/x)/x,",", x ≠ 0),(π/k,",", x = 0):}`

is continuous at x = 0, then k2 is equal to ______.


If f(x) = `{{:((log_(sin|x|) cos^2x)/(log_(sin|3x|) cos  x/2), |x| < π/3; x ≠ 0),(k, x = 0):}`, then value of k for which f(x) is continuous at x = 0 is ______.


If the function f defined as f(x) = `1/x - (k - 1)/(e^(2x) - 1)` x ≠ 0, is continuous at x = 0, then the ordered pair (k, f(0)) is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×