Find the exact value of $\cos \left(\cos ^{-1}(-2)\right)$.
Write your answer in radians in terms of $\pi$. If necessary, click on "Undefined."

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Answer

$\boxed{\text{Undefined}}$

Steps

Step 1 ：The cosine function only takes values between -1 and 1.

Step 2 ：Therefore, the inverse cosine function, or arccosine, is undefined for values less than -1 or greater than 1.

Step 3 ：Since -2 is less than -1, $\cos^{-1}(-2)$ is undefined.

Step 4 ：Therefore, $\cos(\cos^{-1}(-2))$ is also undefined.

Step 5 ：$\boxed{\text{Undefined}}$