Question

Let $f(x) = \begin{cases} cx^2 +2x, & \text{if $x< 2$ } \\ 2x +4, & \text{if $x \ge 2$ } \end{cases}$ If the function $f$ is continuous on $(-\infty, \infty)$, then the value of $c$ is equal to

• A. 4
• B. 2
• C. 3
• D. 1
• E. 5

Answer 1

Answer: (D)

$LHL = RHL$
$\Rightarrow 4 C+4=8$
$\Rightarrow 4 C=4$
$\Rightarrow C=1$