Question
If the function
$f(x)= \begin{cases}\frac{1}{|x|}, & |x| \geqslant 2 \\ \mathrm{a} x^2+2 \mathrm{~b}, & |x|<2\end{cases}$
is differentiable on $\mathbf{R}$, then $48(a+b)$ is equal to __________.
Correct Answer
15
If the function
$f(x)= \begin{cases}\frac{1}{|x|}, & |x| \geqslant 2 \\ \mathrm{a} x^2+2 \mathrm{~b}, & |x|<2\end{cases}$
is differentiable on $\mathbf{R}$, then $48(a+b)$ is equal to __________.