Is $|x|^{3/2}$ differentiable?
The term "continuously differentiable" means that
a. The function is differentiable, and b. The derivative is continuous.
Thus, the second derivative is not relevant here, and the correct option is $1$.
The term "continuously differentiable" means that
a. The function is differentiable, and b. The derivative is continuous.
Thus, the second derivative is not relevant here, and the correct option is $1$.