Home
Class 12
MATHS
Show that the function f(x)={|2x-3|\ [x]...

Show that the function `f(x)={|2x-3|\ [x],\ \ \ xgeq1sin((pix)/2),\ \ \ \ \ \ x<1` is continuous but not differentiable at `x=1` .

Text Solution

Verified by Experts

`f(1)=∣2−3∣[1]=1`
`lim_(h->0) f(1+h) = |2+2h-3|[1+h]`
`=1 xx 1`
`=1`
`lim_(h->0)f(1-h) `
`=sin((pi(1-h))/2)`
`=sin (pi/2)`
`=1`
Hence `f(x)` is continuous at `1.`
For differentiability,
`lim_(h->0)(f(1+h)-f(1))/h` must be equal to `lim_(h->0)(f(1)-f(1-h))/h `
`=>lim_(h->0)(|2+2h-3|[1+h]-|2-3|[1])/h= (|2-3|[1]-sin((pi-h)/2))/h`
`=>(|2h-1|-1)/h=(1-sin((pi-h)/2))/h[0/0 form ]`
Since h is very small,
`(2h−1)` is `−ve`.
`=>(1-2h-1)/h =-cos ((pi-h)/2) xx (-1/2) `
`=> -2 ne 0`
that means function is non-differentiable at 1.
but continuous at 1. Hence proved.
Promotional Banner

Topper's Solved these Questions

  • DETERMINANTS

    RD SHARMA|Exercise Solved Examples And Exercises|403 Videos
  • DIFFERENTIAL EQUATION

    RD SHARMA|Exercise Solved Examples And Exercises|634 Videos

Similar Questions

Explore conceptually related problems

Show that f(x)={{:(|2x-3|[x]", "xge1),(sin((pix)/2)", "xlt1):} is continuous but not differentiable at x = 1.

Show that the function f(x)={|2x-3|[x]x 0 is continuous but not differentiable at x=1

Show that the function f(x)=x^3/2 is not differentiable at x=0.

Show that the function f given by f(x)=x^(3)-3x^(2)+4x,x in R

The range of the function f(x) = (1)/(2-sin 3x) is

Show that the function f(x) given by f(x)={(sin x)/(x)+cos x,x!=0 and 2,x=0 is continuous at x=0

Find the inverse of the function: f(x)={x^3-1, ,x<2x^2+3,xgeq2

Show that the function f(x)= x^(3) - 3x^(2)+3x - 1 is an increasing function on R.

RD SHARMA-DIFFERENTIABILITY-Solved Examples And Exercises
  1. Show that the function f(x)={x^msin(1/x),\ \ \ x!=0 0,\ \ \ \ \ \ \ \ ...

    Text Solution

    |

  2. Find the values of a and b so that the function f(x)={x^2+3x+a ,\ \ if...

    Text Solution

    |

  3. Show that the function f(x)={|2x-3|\ [x],\ \ \ xgeq1sin((pix)/2),\ \ \...

    Text Solution

    |

  4. If f(x)={a x^2-b ,\ \ \ if\ |x|<1 1/(|x|),\ \ \ \ \ \ \ \ \ \ \ \ if\ ...

    Text Solution

    |

  5. Find the values of a and b , if the function f(x) defined by f(x)={x^2...

    Text Solution

    |

  6. If f(x)=x^2+2x+7 , find f\ '\ (3) .

    Text Solution

    |

  7. Find f\ '\ (2) and f\ '\ (5) when f(x)=x^2+7x+4 .

    Text Solution

    |

  8. For the function f given by f(x)=x^2-6x+8 , prove that f\ '\ (5)-3\ f\...

    Text Solution

    |

  9. Discuss the continuity and differentiability of f(x)={1-x ,\ \ \ \ ...

    Text Solution

    |

  10. Discuss the differentiability of f(x)=|x-1|+|x-2|

    Text Solution

    |

  11. If f(x)={x^2+3x+a ,\ \ \ for\ xlt=1b x+2,\ \ \ \ \ \ \ \ \ \ \ \ \ for...

    Text Solution

    |

  12. Discuss the differentiability of f(x)=|(log)e x| x > 0.

    Text Solution

    |

  13. If f is defined by f(x)=x^2 , find f\ '\ (2) .

    Text Solution

    |

  14. If f is defined by f(x)=x^2-4x+7 , show that f\ '\ (5)=2f\ '(7/2)

    Text Solution

    |

  15. Show that the derivative of the function f given by f(x)=2x^3-9x^2+...

    Text Solution

    |

  16. If for the function "Phi"(x)=lambdax^2+7x-4,\ \ "Phiprime^"(5)=97 , fi...

    Text Solution

    |

  17. If f(x)=x^3+7x^2+8x-9 , find f\ '\ (4) .

    Text Solution

    |

  18. Find the derivative of the function f defined by f(x)=m x+c at x=0 ...

    Text Solution

    |

  19. Examine the differentiability of the function f defined by f(x)={2x...

    Text Solution

    |

  20. Write an example of a function which is everywhere continuous but f...

    Text Solution

    |