Home
Class 12
MATHS
Discuss the continutiy of the function ...

Discuss the continutiy of the function
`f(x)= {(3x+5", " x ge 2),(6x-1", " x lt 2):}`

Text Solution

AI Generated Solution

The correct Answer is:
To discuss the continuity of the function \[ f(x) = \begin{cases} 3x + 5 & \text{if } x \geq 2 \\ 6x - 1 & \text{if } x < 2 \end{cases} \] we need to check its continuity at the point \(x = 2\). A function is continuous at a point if the following three conditions are satisfied: 1. \(f(a)\) is defined. 2. \(\lim_{x \to a} f(x)\) exists. 3. \(\lim_{x \to a} f(x) = f(a)\). Here, \(a = 2\). ### Step 1: Calculate \(f(2)\) For \(x = 2\), we use the first case of the function since \(x \geq 2\): \[ f(2) = 3(2) + 5 = 6 + 5 = 11. \] ### Step 2: Calculate \(\lim_{x \to 2^-} f(x)\) Next, we find the left-hand limit as \(x\) approaches 2 from the left (\(x < 2\)). We use the second case of the function: \[ \lim_{x \to 2^-} f(x) = \lim_{x \to 2^-} (6x - 1). \] Substituting \(x = 2\): \[ \lim_{x \to 2^-} f(x) = 6(2) - 1 = 12 - 1 = 11. \] ### Step 3: Calculate \(\lim_{x \to 2^+} f(x)\) Now, we find the right-hand limit as \(x\) approaches 2 from the right (\(x \geq 2\)). We use the first case of the function: \[ \lim_{x \to 2^+} f(x) = \lim_{x \to 2^+} (3x + 5). \] Substituting \(x = 2\): \[ \lim_{x \to 2^+} f(x) = 3(2) + 5 = 6 + 5 = 11. \] ### Step 4: Compare the values Now we compare the three values we have calculated: - \(f(2) = 11\) - \(\lim_{x \to 2^-} f(x) = 11\) - \(\lim_{x \to 2^+} f(x) = 11\) Since all three values are equal, we conclude that: \[ \lim_{x \to 2} f(x) = f(2). \] ### Conclusion Thus, the function \(f(x)\) is continuous at \(x = 2\). ---
Promotional Banner

Topper's Solved these Questions

  • Continuity and Differentiability

    NAGEEN PRAKASHAN ENGLISH|Exercise Exercies 5c|14 Videos
  • Continuity and Differentiability

    NAGEEN PRAKASHAN ENGLISH|Exercise Exercies 5d|51 Videos
  • Continuity and Differentiability

    NAGEEN PRAKASHAN ENGLISH|Exercise Exercies 5a|30 Videos
  • APPLICATIONS OF INTEGRALS

    NAGEEN PRAKASHAN ENGLISH|Exercise Miscellaneous Exercise|19 Videos
  • DETERMINANTS

    NAGEEN PRAKASHAN ENGLISH|Exercise Miscellaneous Exercise|19 Videos

Similar Questions

Explore conceptually related problems

Discuss the continutiy of the function f(x)= {(4x-2", " x le 2),(3x", " x gt 2):}

Discuss the continuity of the function f(x) ={(x", " x ge 0),(2", "x lt0):} at x=0

Discuss the continutiy of the function f(x)= {((sin x)/x", " x lt 0),(2x+3 ", " x ge 0 ):}

Discuss the continuity of the function f(x)={{:(2x -1 "," x lt 1),(3x-2"," x ge 1):}

Discuss of the continutiy of the fuction f(x)={{:(sin x/x ", " x lt 0),(x+2 "," x ge 0):}

Discuss the continuity of the function f(x) ={:{((Sinx)/(x) ", "x lt0 ),(x+1 ", " x ge0):}, at =0.

(i) Dissusse the continuity of the function f(x)={(|x-a|", " xne a ),(" "0 ", "x=a):} at x=a (ii) Discuss the continutiy of the function f(x)={(|x-3|/(x-3)", " xne 3 ),(" "0 ", "x=3):} at x=3

The function f(x)= {(5x-4 ", " 0 lt x le 1 ),( 4x^3-3x", " 1 lt x lt 2):}

Discuss the continuity of the function f(x)= {(x , 0 le x lt1/2 ),( 12,x=1/2),( 1-x , 1/2ltxle1):} at the point x=1//2 .

Discuss the continuity of the function f(x)={2x-1 ,ifx<2, (3x)/2ifxgeq2