Question

What is the inverse cosine of -3 pi

Answer 1

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Answer 2

\[\cos^{-1}(-3\pi)\]?

Answer 3

inverse cosine can only take inputs between -1 and 1.

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Answer 4

I thought that, too, PaxPolaris. However, my teacher got the answer of pi

Answer 5

then the question would have to be what's the inverse cosine of the cosine of - 3pi.

Answer 6

Oh, alright! Thanks so much, that makes a lot more sense. My teacher must have meant to write that.

Answer 7

Am I allowed to ask you another question about inverse trigonometric functions?