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For what value of k, the function f(x)...

For what value of k, the function
`f(x) ={:{((x^2-4)/(x-2)", " x ne 2),(" "k", " x=2):},`
is continuous at x =2.

A

0

B

4

C

6

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To determine the value of \( k \) for which the function \[ f(x) = \begin{cases} \frac{x^2 - 4}{x - 2} & \text{if } x \neq 2 \\ k & \text{if } x = 2 \end{cases} \] is continuous at \( x = 2 \), we need to ensure that the limit of \( f(x) \) as \( x \) approaches 2 equals \( f(2) \). ### Step 1: Find the limit of \( f(x) \) as \( x \) approaches 2. We start by simplifying the expression for \( f(x) \) when \( x \neq 2 \): \[ f(x) = \frac{x^2 - 4}{x - 2} \] Notice that \( x^2 - 4 \) can be factored: \[ x^2 - 4 = (x - 2)(x + 2) \] Thus, we can rewrite \( f(x) \): \[ f(x) = \frac{(x - 2)(x + 2)}{x - 2} = x + 2 \quad \text{for } x \neq 2 \] ### Step 2: Calculate the limit as \( x \) approaches 2. Now, we find the limit: \[ \lim_{x \to 2} f(x) = \lim_{x \to 2} (x + 2) = 2 + 2 = 4 \] ### Step 3: Set the limit equal to \( f(2) \). For the function to be continuous at \( x = 2 \), we need: \[ \lim_{x \to 2} f(x) = f(2) \] This gives us: \[ 4 = k \] ### Conclusion: Thus, the value of \( k \) that makes the function continuous at \( x = 2 \) is: \[ \boxed{4} \] ---

To determine the value of \( k \) for which the function \[ f(x) = \begin{cases} \frac{x^2 - 4}{x - 2} & \text{if } x \neq 2 \\ k & \text{if } x = 2 \end{cases} ...
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