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## goongmax 3 years ago arccos(cos(94pi/59))

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1. micahwood50

HINT: $\cos^{-1} (\cos x) = x$

2. goongmax

arccos(cos(94pi/59)) = 94pi/59

3. zepdrix

|dw:1351301061848:dw|

4. goongmax

94pi/59 is in the 4th quad. so... 94pi/59 -pi = 35/59 pi

5. TransendentialPI

We know the range of the arc cosine function is limited to [0,pi], right? We know that 90pi/59 is pretty close to 90pi/60 or 3pi/2. The cos(3pi/2) is close to 0 The arccos(0) is pi/2 The reference angle for the 90pi/59 would be in quad 4 and measure 28/59 pi. SO I'm thiniking the answer to the problem would be 28pi/59|dw:1351301172847:dw|

6. TransendentialPI

Glad to see I was thinking about that correctly.

7. zepdrix

Oh sorry trans.. you were typing really long :C wasn't sure if you were going to paste anything. Didn't mean to step on yer toes there XD

8. goongmax

OMG wrong lol. its 2pi - 94/59pi

9. goongmax

ans: 24/59pi

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