Home
Class 12
MATHS
If f(x)=|2-x|+(2+x), where (x)=the least...

If `f(x)=|2-x|+(2+x)`, where (x)=the least integer greater than or equal to x, them

A

`underset(x to 2^(-))lim f(x)=f(2)=2`

B

f(x) is continuous and differentiable at x=2

C

f(x) is neither continuous nor differentiable at x=2

D

f(x) is continuous and non-differentiable at x=2

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the function \( f(x) = |2 - x| + \lfloor 2 + x \rfloor \), where \( \lfloor x \rfloor \) denotes the greatest integer less than or equal to \( x \). ### Step 1: Evaluate the function at \( x = 2 \) First, we calculate \( f(2) \): \[ f(2) = |2 - 2| + \lfloor 2 + 2 \rfloor = |0| + \lfloor 4 \rfloor = 0 + 4 = 4 \] ### Step 2: Calculate the left-hand limit as \( x \) approaches 2 Next, we find the left-hand limit \( \lim_{x \to 2^-} f(x) \): For \( x < 2 \): \[ f(x) = |2 - x| + \lfloor 2 + x \rfloor = (2 - x) + \lfloor 2 + x \rfloor \] As \( x \) approaches 2 from the left, \( 2 + x \) approaches 4, which is an integer. Thus, \( \lfloor 2 + x \rfloor = 4 \) for \( x \) just less than 2. Now substituting this into the equation: \[ \lim_{x \to 2^-} f(x) = (2 - 2) + 4 = 0 + 4 = 4 \] ### Step 3: Compare the left-hand limit with the value of the function at \( x = 2 \) We have: \[ \lim_{x \to 2^-} f(x) = 4 \quad \text{and} \quad f(2) = 4 \] Since both the left-hand limit and the function value at \( x = 2 \) are equal, we can conclude that the function is continuous at \( x = 2 \). ### Step 4: Check differentiability at \( x = 2 \) To check differentiability, we need to consider the derivative from the left and right: 1. For \( x < 2 \): \[ f(x) = (2 - x) + 4 \implies f'(x) = -1 \] 2. For \( x > 2 \): \[ f(x) = |2 - x| + \lfloor 2 + x \rfloor = (x - 2) + \lfloor 2 + x \rfloor \] As \( x \) approaches 2 from the right, \( \lfloor 2 + x \rfloor = 4 \) as well, so: \[ f(x) = (x - 2) + 4 \implies f'(x) = 1 \] Since the left-hand derivative \( f'(2^-) = -1 \) and the right-hand derivative \( f'(2^+) = 1 \) are not equal, \( f(x) \) is not differentiable at \( x = 2 \). ### Conclusion - The function \( f(x) \) is continuous at \( x = 2 \) but not differentiable at that point. - Therefore, the correct option is that \( f(x) \) is continuous and non-differentiable at \( x = 2 \). ### Final Answer The function \( f(x) \) is continuous and non-differentiable at \( x = 2 \). ---

To solve the problem, we need to analyze the function \( f(x) = |2 - x| + \lfloor 2 + x \rfloor \), where \( \lfloor x \rfloor \) denotes the greatest integer less than or equal to \( x \). ### Step 1: Evaluate the function at \( x = 2 \) First, we calculate \( f(2) \): \[ f(2) = |2 - 2| + \lfloor 2 + 2 \rfloor = |0| + \lfloor 4 \rfloor = 0 + 4 = 4 \] ...
Promotional Banner

Topper's Solved these Questions

  • CONTINUITY AND DIFFERENTIABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|13 Videos
  • CONTINUITY AND DIFFERENTIABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|87 Videos
  • CONTINUITY AND DIFFERENTIABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|87 Videos
  • COMPLEX NUMBERS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|58 Videos
  • DEFINITE INTEGRALS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test 2|56 Videos

Similar Questions

Explore conceptually related problems

If f(x)=|3-x|+(3+x), where (x) denotes the least integer greater than or equal to x , then f(x) is continuous and differentiable at x=3 continuous but not differentiable at x=3 differentiable but not continuous at x=3 neither differentiable nor continuous at x=3

If f(x)=|3-x|+[3+x] , where [x] denotes the least integer greater than or equal to x , then f(x) is:(a) continuous and differentiable at x=3. (b) continuous but not differentiable at x=3. (c)differentiable but not continuous at x=3. (d)neither differentiable nor continuous at x=3..

If f(x)=|x|+[x] , where [x] is the greatest integer less than or equal to x, the value of f(-2.5)+f(1.5) is

If f(x)=|x-1|-[x] , where [x] is the greatest integer less than or equal to x, then

The solution set of the equation (x)^(2)+[x]^(2)=(x-1)^(2)+[x+1]^(2) , where (x) denotes the least integer greater than or equal to x and [x] denotes the greatest integer less than or equal to x, is

If [x]^(2)=[x+2] , where [x]=the greatest integer integer less than or equal to x, then x must be such that

If [x]^(2)=[x+6] , where [x]= the greatest integer less than or equal to x, then x must be such that

The solution set of x which satisfies the equation x^2 + (x+1)^2 = 25 where (x) is a least integer greater than or equal to x

If [.] denotes the greatest integer less than or equal to x and (.) denotes the least integer greater than or equal to x, then domain of the function f(x)=sin^(-1){x+[x]+(x)} is

If the function f: R->R be such that f(x) = x-[x], where [x] denotes the greatest integer less than or equal to x, then f^-1(x) is

OBJECTIVE RD SHARMA ENGLISH-CONTINUITY AND DIFFERENTIABILITY-Section I - Solved Mcqs
  1. Let f((x+y)/(2))= (f(x)+f(y))/(2) for all real x and y. If f'(0) exits...

    Text Solution

    |

  2. Let f:R to R be given by f(x+y)=f(x)-f(y)+2xy+1"for all "x,y in R If f...

    Text Solution

    |

  3. If f(x)=|2-x|+(2+x), where (x)=the least integer greater than or equal...

    Text Solution

    |

  4. If f(x)=([x])/(|x|),x ne 0 where [.] denotes the greatest integer func...

    Text Solution

    |

  5. If 4x+3|y|=5y, then y as a function of x is

    Text Solution

    |

  6. Let f(x)=log(e)|x-1|, x ne 1, then the value of f'((1)/(2)) is

    Text Solution

    |

  7. Let a function f(x) defined on [3,6] be given by f(x)={{:(,log(e)[x],3...

    Text Solution

    |

  8. If f(x)={{:(,e^(x),x lt 2),(,ax+b,x ge 2):} is differentiable for all ...

    Text Solution

    |

  9. If the function f(x) is given by f(x)={{:(,2^(1//(x-1)),x lt 1),(,ax^(...

    Text Solution

    |

  10. Let f(x)=sin x,g(x)=[x+1] and h(x)=gof(x) where [.] the greatest integ...

    Text Solution

    |

  11. If f(x)=|x-2| and g(x)=f[f(x)], then g'(x)=………… for x gt20.

    Text Solution

    |

  12. If f(x)=sgn(x)={(|x|)/x,x!=0, 0, x=0 and g(x)=f(f(x)),then at x=0,g(x)...

    Text Solution

    |

  13. Let f(x)=cos x and g(x)=[x+1],"where [.] denotes the greatest integer ...

    Text Solution

    |

  14. f(x)=min{1,cosx,1-sinx},-pilexlepi, then

    Text Solution

    |

  15. If [.] denotes the greatest integer function, then f(x)=[x]+[x+(1)/(2)...

    Text Solution

    |

  16. If f(x) = sgn(x^5), then which of the following is/are false (where sg...

    Text Solution

    |

  17. If f (x) =|x-1|and g (x) =f (f (f (x))), then g' (x) is equal to:

    Text Solution

    |

  18. If f(x)={{:(,(1)/(x)-(2)/(e^(2x)-1),x ne 0),(,1,x=0):}

    Text Solution

    |

  19. Let f(x)=(-1)^([x^(3)]), where [.] denotest the greatest integer funct...

    Text Solution

    |

  20. f(x)=(1)/(1-x)and f^(n)=fofof....of, then the points of discontinuitym...

    Text Solution

    |