Determine the value of '$k$' for which the following function is continuous at $x = 3$: $f(x) = \begin{cases} \frac{(x + 3)^2 - 36}{x - 3}, & x \neq 3 \\ k, & x = 3 \end{cases}$ |
$k = 6$ $k = 9$ $k = 12$ $k = 36$ |
$k = 12$ |
The correct answer is Option (3) → $k = 12$ ## $f(x) = \begin{cases} \frac{(x + 3)^2 - 36}{x - 3} & ; x \neq 3 \\ k & ; x = 3 \end{cases}$ $f(x)$ is continuous at $x = 3$ $\lim\limits_{x \to 3^-} f(x) = \lim\limits_{x \to 3^+} f(x) = f(3)$ $\lim\limits_{x \to 3} \frac{(x + 3)^2 - (6)^2}{x - 3} = k$ $\lim\limits_{x \to 3} \frac{(x + 3 - 6)(x + 3 + 6)}{(x - 3)} = k$ $\lim\limits_{x \to 3} \frac{(x - 3)(x + 9)}{(x - 3)} = k$ $\lim\limits_{x \to 3} (x + 9) = k$ $12 = k$ $k = 12$ |