Home
Class 12
MATHS
Consider, f(x) = {{:(x^(2)/(|x|), x ne 0...

Consider, `f(x) = {{:(x^(2)/(|x|), x ne 0),(0, x =0):}`

A

f(x) is discontinuous everywhere

B

f(x) is continuous everywhere

C

f'(x) exists in (-1,1}

D

f'(x) exists in (- 2,2)

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the function given by: \[ f(x) = \begin{cases} \frac{x^2}{|x|} & \text{if } x \neq 0 \\ 0 & \text{if } x = 0 \end{cases} \] ### Step 1: Simplify the function for \(x \neq 0\) For \(x > 0\), \(|x| = x\), so: \[ f(x) = \frac{x^2}{x} = x \quad \text{for } x > 0 \] For \(x < 0\), \(|x| = -x\), so: \[ f(x) = \frac{x^2}{-x} = -x \quad \text{for } x < 0 \] Thus, we can rewrite the function as: \[ f(x) = \begin{cases} x & \text{if } x > 0 \\ -x & \text{if } x < 0 \\ 0 & \text{if } x = 0 \end{cases} \] ### Step 2: Check continuity at \(x = 0\) To check if \(f(x)\) is continuous at \(x = 0\), we need to find the left-hand limit and the right-hand limit as \(x\) approaches \(0\). **Left-hand limit** as \(x \to 0^{-}\): \[ \lim_{x \to 0^{-}} f(x) = \lim_{x \to 0^{-}} (-x) = 0 \] **Right-hand limit** as \(x \to 0^{+}\): \[ \lim_{x \to 0^{+}} f(x) = \lim_{x \to 0^{+}} x = 0 \] Since both limits are equal to \(f(0)\): \[ f(0) = 0 \] Thus, \(f(x)\) is continuous at \(x = 0\). ### Step 3: Check continuity everywhere Since \(f(x)\) is defined piecewise and both pieces are continuous for \(x > 0\) and \(x < 0\), we conclude that \(f(x)\) is continuous everywhere. ### Step 4: Check differentiability at \(x = 0\) Now we need to check if \(f(x)\) is differentiable at \(x = 0\). **Left-hand derivative** at \(x = 0\): \[ f'(0^{-}) = \lim_{h \to 0^{-}} \frac{f(h) - f(0)}{h} = \lim_{h \to 0^{-}} \frac{-h - 0}{h} = -1 \] **Right-hand derivative** at \(x = 0\): \[ f'(0^{+}) = \lim_{h \to 0^{+}} \frac{f(h) - f(0)}{h} = \lim_{h \to 0^{+}} \frac{h - 0}{h} = 1 \] Since the left-hand derivative \(-1\) and the right-hand derivative \(1\) are not equal, \(f(x)\) is not differentiable at \(x = 0\). ### Conclusion 1. **Continuity**: The function \(f(x)\) is continuous everywhere. 2. **Differentiability**: The function \(f(x)\) is not differentiable at \(x = 0\). ### Final Answer - \(f(x)\) is continuous everywhere. - \(f(x)\) is not differentiable at \(x = 0\). ---
Promotional Banner

Topper's Solved these Questions

  • LIMITS, CONTINUITY AND DIFFERENTIABILITY

    ML KHANNA|Exercise PROBLEM SET (2) (TRUE AND FALSE) |4 Videos
  • LIMITS, CONTINUITY AND DIFFERENTIABILITY

    ML KHANNA|Exercise PROBLEM SET (2) (FILL IN THE BLANKS) |2 Videos
  • LIMITS, CONTINUITY AND DIFFERENTIABILITY

    ML KHANNA|Exercise PROBLEM SET (1) (FILL IN THE BLANKS) |7 Videos
  • INVERSE CIRCULAR FUNCTIONS

    ML KHANNA|Exercise Self Assessment Test|25 Videos
  • LINEAR PROGRAMMING

    ML KHANNA|Exercise Self Assessment Test|8 Videos

Similar Questions

Explore conceptually related problems

Let f(x)={{:(x sin.(1)/(x)",",x ne0),(0",",x=0):}} and g(x)={{:(x^(2)sin.(1)/(x)",", x ne 0),(0",", x=0):}} Discuss the graph for f(x) and g(x), and evaluate the continuity and differentiabilityof f(x) and g(x).

The function f defined by f(x)={{:(,(sinx^(2))/(x),x ne 0),(,0,x=0):} is

f(x) = {{:(x^(2)sin'1/x, if x ne 0),(0, if x = 0):} at x = 0 .

If f(x)={:{(xe^(-(1/(|x|) + 1/x)), x ne 0),(0 , x =0 ):} then f(x) is

Examine the continuity of f(x) = {((sin2x)/(2x), x ne 0),(2, x = 0):} at x = 0

ML KHANNA-LIMITS, CONTINUITY AND DIFFERENTIABILITY -PROBLEM SET (2) (MULTIPLE CHOICE QUESTIONS)
  1. f(x)=||x|-1| is not differentiable at

    Text Solution

    |

  2. The number of points at which the function f(x) =|x-0.5|+|x-1| + tan x...

    Text Solution

    |

  3. Consider, f(x) = {{:(x^(2)/(|x|), x ne 0),(0, x =0):}

    Text Solution

    |

  4. The function f(x) = (x^(2)-1)|x^(2) -3x+2| + cos(|x|) is not differen...

    Text Solution

    |

  5. Consider the following statements S and R: S: Both sin x and cos x a...

    Text Solution

    |

  6. If f(x) =x^(2) + x^(2)/(1+x^(2)) + x^(2)/(1+x^(2))^(2) + …… + x^(2)/(1...

    Text Solution

    |

  7. Let f(x) be a function satisfying f(x+y)=f(x)+f(y) and f(x)=x g(x)"For...

    Text Solution

    |

  8. Let f(x + y)=f(x)+f (y) and f(x) = x^2 g(x) for all x, y in R, where g...

    Text Solution

    |

  9. A differentiable function f (x) satisfies the condition f(x+y) =f(x) +...

    Text Solution

    |

  10. Let f(x + y) = f(x) f (y) for all x and y. Suppose that f(3) = 3 and f...

    Text Solution

    |

  11. Let f(x+y)=f(x) f(y) and f(x)=1+(sin 2x)g(x) where g(x) is continuous....

    Text Solution

    |

  12. Suppose the function f satisfies the conditions : (i) f(x+y) =f(x) f...

    Text Solution

    |

  13. A function f: R to R satisfies the equation f(x+y) =f(x) f(y) for al...

    Text Solution

    |

  14. If f is twice differentiable function such that f''(x) =-f(x), and f...

    Text Solution

    |

  15. Let F(x) =(f(x/2))^(2) +(g(x/2))^(2). F(5)=5 and f''(x) =-f(x), g(x) =...

    Text Solution

    |

  16. If f'(x)=g(x) and g'(x)=-f(x) for all x and f(2) =4 =f'(2) then f^(2)(...

    Text Solution

    |

  17. Let f(x+y) =f(x)f(y) for all x and y. Suppose f(5)=2 and f' (0) = 3, ...

    Text Solution

    |

  18. Let f be a continuous function on [1,3] which takes rational values fo...

    Text Solution

    |

  19. Let f(x) be differentiable AA x. If f(1)=-2 and f'(x) ge 2 AA x in x[1...

    Text Solution

    |

  20. If f is a real valued differentiable function satisfying |f(x) -f(y)|...

    Text Solution

    |