Consider the following for the two (02) items that follow: Let the function $f(x)=\sin [x]$, where [⋅] is the greatest integer function and $g(x)=|x|$.

What $\lim_{x \to 0} {f(x) g(x)}$ is  equal to?

Consider the following for the two (02) items that follow: Let the function $f(x)=\sin [x]$, where [⋅] is the greatest integer function and $g(x)=|x|$.

What is $\lim_{x \to 0} \frac{f(x)}{g(x)}$ equal to?

Consider the following for the two (02) items that follow :
Let the function f(x) = x²- 1

What is $\lim_{x \to 1} \{f \circ f(x)\}$ equal to?

Consider the following for the two (02) items that follow:
Let the function f(x) = x ² + 9

What is  $\lim_{x \to 0} \frac{\sqrt{f(x)} - 3}{\sqrt{f(x)+7} - 4}$ equal to?