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?

Which one of the following is correct regarding $\rm \lim\limits_{x\rightarrow 3}\frac{|x-3|}{x-3}$?

What is $\rm \lim\limits_{x\rightarrow \frac{\pi}{2}}(\sec \theta-\tan \theta)$ equal to?