Question 968430
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What is the exact value of arccos(cos(3π/2) )
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This problem is a simple elementary   {{{highlight(highlight(TRAP))}}}.   It provokes you to answer  " {{{3pi/2}}} ",  but this answer is  WRONG.


<pre>
To answer correctly, you should remember that function arccos has values in interval  [{{{-pi/2}}},{{{pi/2}}}].


Therefore, you should transform  {{{3pi/2}}}  to the equivalent angle in interval  [{{{-pi/2}}},{{{pi/2}}}].


This equivalent angle is  {{{-pi/2}}},  so the correct answer to the problem's question is  {{{-pi/2}}}.
</pre>

Solved.


Be accurate and attentive in order for do not fall in this and similar traps.