## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$\text{Not defined}$
Value of certain composite functions formula: $f(f^{-1}(x)) = \cos{(\cos^{-1}{x})}= x \hspace{25pt} -1 \leq x \leq 1$ Note that $1.2 \text{ isn't in the interval } \left[-1,1 \right]$. $\therefore \cos{(\cos^{-1}{(1.2)})} \text{ isn't defined}$.