# How do you find #theta# if #costheta=2#?

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I know that the cosine function taken over the reals only has values between #-1# and #1# . However, I think there is some complex value of #theta# for any complex output of a sine or cosine function. How would you find such a value?

I know that the cosine function taken over the reals only has values between

##### 1 Answer

Apr 9, 2018

The reference Inverse Trigonometric Functions gives us the complex form of the inverse cosine function:

#### Explanation:

Given: