Home
Class 12
MATHS
For what values a and b f(x)={{:(,(x+2)/...

For what values a and b `f(x)={{:(,(x+2)/(|x+2|)+a,if x lt -2),(,a+b,if x=-2),(,(x+2)/(|x+2|)+2b, if x gt -2):}` Is continuous at x=-2

Text Solution

AI Generated Solution

The correct Answer is:
To determine the values of \( a \) and \( b \) for which the function \[ f(x) = \begin{cases} \frac{x+2}{|x+2|} + a & \text{if } x < -2 \\ a + b & \text{if } x = -2 \\ \frac{x+2}{|x+2|} + 2b & \text{if } x > -2 \end{cases} \] is continuous at \( x = -2 \), we need to ensure that the left-hand limit, right-hand limit, and the function value at \( x = -2 \) are all equal. ### Step 1: Calculate the left-hand limit as \( x \) approaches -2 The left-hand limit is given by: \[ \lim_{x \to -2^-} f(x) = \lim_{x \to -2^-} \left( \frac{x+2}{|x+2|} + a \right) \] For \( x < -2 \), \( |x+2| = -(x+2) \), so we have: \[ \frac{x+2}{|x+2|} = \frac{x+2}{-(x+2)} = -1 \] Thus, the left-hand limit becomes: \[ \lim_{x \to -2^-} f(x) = -1 + a \] ### Step 2: Calculate the right-hand limit as \( x \) approaches -2 The right-hand limit is given by: \[ \lim_{x \to -2^+} f(x) = \lim_{x \to -2^+} \left( \frac{x+2}{|x+2|} + 2b \right) \] For \( x > -2 \), \( |x+2| = x+2 \), so we have: \[ \frac{x+2}{|x+2|} = \frac{x+2}{x+2} = 1 \] Thus, the right-hand limit becomes: \[ \lim_{x \to -2^+} f(x) = 1 + 2b \] ### Step 3: Evaluate the function at \( x = -2 \) At \( x = -2 \), the function value is: \[ f(-2) = a + b \] ### Step 4: Set the limits and function value equal For \( f(x) \) to be continuous at \( x = -2 \), we need: \[ \text{Left-hand limit} = \text{Right-hand limit} = f(-2) \] This gives us the following equations: 1. \( -1 + a = 1 + 2b \) 2. \( -1 + a = a + b \) ### Step 5: Solve the equations From equation (2): \[ -1 + a = a + b \implies -1 = b \implies b = -1 \] Substituting \( b = -1 \) into equation (1): \[ -1 + a = 1 + 2(-1) \implies -1 + a = 1 - 2 \implies -1 + a = -1 \implies a = 0 \] ### Conclusion The values of \( a \) and \( b \) for which the function is continuous at \( x = -2 \) are: \[ \boxed{a = 0, b = -1} \]
Promotional Banner

Topper's Solved these Questions

  • CONTINUITY AND DIFFERENTIABILTY

    CBSE COMPLEMENTARY MATERIAL|Exercise 2 Marks Questions|20 Videos
  • APPLICATIONS OF INTEGRALS

    CBSE COMPLEMENTARY MATERIAL|Exercise FOUR/SIX MARK QUESTIONS|26 Videos
  • DIFFERENTIAL EQUATIONS

    CBSE COMPLEMENTARY MATERIAL|Exercise SIX MARK QUESTIONS|4 Videos

Similar Questions

Explore conceptually related problems

If f(x) = {((x-2)/(|x-2|)+a, ",",x lt2),(a+b, ",", x = 2 ),((x-2)/(|x-2|)+b, ",",x gt 2):} is continuous at x = 2, then a+b =

Let f: R to R be a function defined as f(x)={(,(sin (a+1)x+sin 2x)/(2x), if x lt 0),(, b, if x=0), (,(sqrt(x+bx^(3))-sqrtx)/(bx^(5/2)), if x gt 0):} If f is continuous at x=0 then the value of a+b is equal to :

If f(x)={:{(2x", if " x lt 2),(2", if " x=2),(x^(2)", if " x gt2):} , then

Show that f(x) =x^(2) is continuous at x=2 lt

show that f(x) ={{:( (2x-1)",",if , x lt2),( (3x)/2",,if x ge 2):} is continuous

If f(x) {:(= 2x - 1 ", if " x gt 2 ),(= 2k ", if " x = 2 ), (=x^(2)-1", if " x lt 2 ) :} is continuous on R , then k = …….

f(x) ={((x^2-9)/(x-3)+a,",",x gt 3),(5, ",",x = 3),(2x^2+3x+b, ",",x lt 3):} is continuous at x = 3, then

The function f(x) = {(x+2, ",",1 le x lt 2),(4, ",", x = 2 ),(3x-2, ",", x gt 2 ):} is continuous at

Find the value of a + b if f(x) = {((a e^(1//|x+2|) - 1)/(2-e^(1//|x+2|)),; -3 lt x lt -2), (b,; x = -2), (sin((x^4-16)/(x^5+32)),; -2 lt x lt 0):} is continuous at x = -2.

CBSE COMPLEMENTARY MATERIAL-CONTINUITY AND DIFFERENTIABILTY-4 Marks Questions
  1. For what values of constant K, the following functions are continuous ...

    Text Solution

    |

  2. For what values of constant K, the following functions are continuous ...

    Text Solution

    |

  3. For what values a and b f(x)={{:(,(x+2)/(|x+2|)+a,if x lt -2),(,a+b,if...

    Text Solution

    |

  4. Determine the values of a ,\ b ,\ c for which the function f(x)={(s...

    Text Solution

    |

  5. f(x)={{:(,[x]+[-x], x ne 0),(,lambda,x=0):} Find the value of lambda...

    Text Solution

    |

  6. Let f(x)={{:((1-sin^(3)x)/(3cos^(2)x),"if "x lt(pi)/(2)),(a,"if "x=(pi...

    Text Solution

    |

  7. If f(x)={x^2+3x+a ,xlt=1b x+2,forx >1 is everywhere differentiable, f...

    Text Solution

    |

  8. Find the realtionship between a and b so that the function defined by ...

    Text Solution

    |

  9. Differentiate tan^(-1)((sqrt(1-x^(2)))/(x)) w.r.t. cos^(-1)(2xsqrt(1-x...

    Text Solution

    |

  10. If y=x^(x^(x)), "then find "(dy)/(dx).

    Text Solution

    |

  11. Differentiate (x cos x)^(x)+(x sin x)^(1/x) w.r.t.x.

    Text Solution

    |

  12. If x^m y^n=(x+y)^(m+n) , prove that (dy)/(dx)=y/x .

    Text Solution

    |

  13. If (x-y)dot(x-y)/x=a , Prove that y(dy)/(dx)+x=2ydot

    Text Solution

    |

  14. If x=tan(1/alogy) , show that (1+x^2)(d^2y)/(dx^2)+(2x-a)(dy)/(dx)=0 .

    Text Solution

    |

  15. If y=xlog"{"x/((a+b x))"]" , then show that x^3(d^2y)/(dx^2)=(x(dy)/(d...

    Text Solution

    |

  16. Differentiate sin^(-1){(2^(x+1). 3^x)/(1+(36)^x)}"w i t hr e s p e...

    Text Solution

    |

  17. If sqrt(1-x^6)+sqrt(1-x^6)=a(x^3-y^3), then prove that (dy)/(dx)=(x^2)...

    Text Solution

    |

  18. If f(x)=sqrt(x^2+1),\ \ g(x)=(x+1)/(x^2+1) and h(x)=2x-3 , then find f...

    Text Solution

    |

  19. If x=s e ctheta-costhetaa n dy=sec^ntheta-cos^ntheta,p rov et h a t ...

    Text Solution

    |

  20. If x^(y)+y^(x)+x^(x)=m^(n)." then find the value of "(dy)/(dx).

    Text Solution

    |