Question 968430
.
What is the exact value of arccos(cos(3π/2) )
~~~~~~~~~~~~~~~~~~~~~~~



        The answer  "3pi/2"  in the post by @lwsshak3 is INCORRECT.



<pre>
This problem is a simple elementary  {{{highlight(highlight(TRAP))}}},  and @lwsshak3 fell in this trap.


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>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Solved correctly, while the "solution" by @lwsshak3 is disproved.