Question

Is this statement true or not? cos (cos^-1 (2)) = 2 Explain why or why not.

Answer 1

True

1) Let's evaluate that, using one identity for that:

$\begin{gathered} \cos (\cos ^{-1}(2))= \\ \cos (\cos ^{-1}(\theta))=\theta \\ \cos (\cos ^{-1}(2))=2 \end{gathered}$

2) Since the cosine of the arc cosine (theta) is equal to theta, we can state that this trigonometric equation is true.

3) Hence, that's true.