Consider the function f(x)={sin(ax)xx<0x2+4x≥0f(x) = \begin{cases} \frac{\sin(ax)}{x} & x < 0 \\ x^2 + 4 & x \geq 0 \end{cases}f(x)={xsin(ax)x2+4x<0x≥0. For what value of aaa is f(x)f(x)f(x) continuous at x=0x = 0x=0?
a=2a = 2a=2
a=4a = 4a=4
a=−4a = -4a=−4
a=±4a = \pm 4a=±4