SOLUTION: how do i evaluate arccos(cos 7pi/2) using the properties of inverse functions?

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Question 431008: how do i evaluate arccos(cos 7pi/2) using the properties of inverse functions?
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Arccosine and cosine are inverses of each other, so arccos%28cos%287pi%2F2%29%29 would be equal to 7pi%2F2. However, since the arccosine function restricts the range (since an infinite number of values are obtained), we say that this arccos%28cos%287pi%2F2%29%29+=+pi%2F2. Depending on the context of the problem, either answer could be correct, or even some general answer in the form pi%2F2+%2B+2k%2Api.