How do you evaluate $cos^-1(cos((11pi)/10))$ ?

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Answer 1 · 2016-07-13T04:28:47

The operand $(11pi)/10$ .

If $y = f(x), x =f^(-1)(y). f f^(-1)y = y and f^(-1)f(x)=x$ ,

Here, $f = cos, f^(-1)=cos^(-1) and x=(11pi)/10$

So, $cos^(-1)cos ((11pi)/10)$ retiurns the operand $(11pi)/10$ .'

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