How do you evaluate $cos(cos^-1(1.1))$ ?

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Answer 1 · 2016-12-01T15:22:01

$cos(cos^-1(1.1))$ cannot be evaluated

$y=cos^-1(x)$ is defined as the number $y$ for which $cos y = x$ .

As the range of $cos x$ is $[-1,1]$ there is no number for which $cos y = 1.1$

Therefore $cos(cos^-1(1.1))$ is not defined.

How do you evaluate cos(cos^-1(1.1))cos(cos^-1(1.1))?